diff --git a/.changeset/sweet-ants-care.md b/.changeset/sweet-ants-care.md
new file mode 100644
index 000000000000..b4805626ab4e
--- /dev/null
+++ b/.changeset/sweet-ants-care.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: rework binding ownership validation
diff --git a/documentation/docs/98-reference/.generated/client-warnings.md b/documentation/docs/98-reference/.generated/client-warnings.md
index 284e9a7c3e57..77d1df4cdde2 100644
--- a/documentation/docs/98-reference/.generated/client-warnings.md
+++ b/documentation/docs/98-reference/.generated/client-warnings.md
@@ -161,7 +161,7 @@ Tried to unmount a component that was not mounted
 ### ownership_invalid_binding
 
 ```
-%parent% passed a value to %child% with `bind:`, but the value is owned by %owner%. Consider creating a binding between %owner% and %parent%
+%parent% passed property `%prop%` to %child% with `bind:`, but its parent component %owner% did not declare `%prop%` as a binding. Consider creating a binding between %owner% and %parent% (e.g. `bind:%prop%={...}` instead of `%prop%={...}`)
 ```
 
 Consider three components `GrandParent`, `Parent` and `Child`. If you do `<GrandParent bind:value>`, inside `GrandParent` pass on the variable via `<Parent {value} />` (note the missing `bind:`) and then do `<Child bind:value>` inside `Parent`, this warning is thrown.
@@ -171,11 +171,7 @@ To fix it, `bind:` to the value instead of just passing a property (i.e. in this
 ### ownership_invalid_mutation
 
 ```
-Mutating a value outside the component that created it is strongly discouraged. Consider passing values to child components with `bind:`, or use a callback instead
-```
-
-```
-%component% mutated a value owned by %owner%. This is strongly discouraged. Consider passing values to child components with `bind:`, or use a callback instead
+Mutating unbound props (`%name%`, at %location%) is strongly discouraged. Consider using `bind:%prop%={...}` in %parent% (or using a callback) instead
 ```
 
 Consider the following code:
diff --git a/packages/svelte/messages/client-warnings/warnings.md b/packages/svelte/messages/client-warnings/warnings.md
index 943cf6f01f4f..f8e9ebd8a047 100644
--- a/packages/svelte/messages/client-warnings/warnings.md
+++ b/packages/svelte/messages/client-warnings/warnings.md
@@ -132,7 +132,7 @@ During development, this error is often preceeded by a `console.error` detailing
 
 ## ownership_invalid_binding
 
-> %parent% passed a value to %child% with `bind:`, but the value is owned by %owner%. Consider creating a binding between %owner% and %parent%
+> %parent% passed property `%prop%` to %child% with `bind:`, but its parent component %owner% did not declare `%prop%` as a binding. Consider creating a binding between %owner% and %parent% (e.g. `bind:%prop%={...}` instead of `%prop%={...}`)
 
 Consider three components `GrandParent`, `Parent` and `Child`. If you do `<GrandParent bind:value>`, inside `GrandParent` pass on the variable via `<Parent {value} />` (note the missing `bind:`) and then do `<Child bind:value>` inside `Parent`, this warning is thrown.
 
@@ -140,9 +140,7 @@ To fix it, `bind:` to the value instead of just passing a property (i.e. in this
 
 ## ownership_invalid_mutation
 
-> Mutating a value outside the component that created it is strongly discouraged. Consider passing values to child components with `bind:`, or use a callback instead
-
-> %component% mutated a value owned by %owner%. This is strongly discouraged. Consider passing values to child components with `bind:`, or use a callback instead
+> Mutating unbound props (`%name%`, at %location%) is strongly discouraged. Consider using `bind:%prop%={...}` in %parent% (or using a callback) instead
 
 Consider the following code:
 
diff --git a/packages/svelte/src/compiler/phases/2-analyze/index.js b/packages/svelte/src/compiler/phases/2-analyze/index.js
index 1f636c32df6d..c62fb03e8fef 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/index.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/index.js
@@ -432,6 +432,7 @@ export function analyze_component(root, source, options) {
 		uses_component_bindings: false,
 		uses_render_tags: false,
 		needs_context: false,
+		needs_mutation_validation: false,
 		needs_props: false,
 		event_directive_node: null,
 		uses_event_attributes: false,
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js b/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js
index 0bdfbae746d0..38fcee8d6fca 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js
@@ -393,6 +393,12 @@ export function client_component(analysis, options) {
 		);
 	}
 
+	if (analysis.needs_mutation_validation) {
+		component_block.body.unshift(
+			b.var('$$ownership_validator', b.call('$.create_ownership_validator', b.id('$$props')))
+		);
+	}
+
 	const should_inject_context =
 		dev ||
 		analysis.needs_context ||
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/utils.js b/packages/svelte/src/compiler/phases/3-transform/client/utils.js
index 28e3fabb1990..a37ecd31cc03 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/utils.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/utils.js
@@ -1,10 +1,10 @@
-/** @import { ArrowFunctionExpression, Expression, FunctionDeclaration, FunctionExpression, Identifier, Pattern, PrivateIdentifier, Statement } from 'estree' */
-/** @import { AST, Binding } from '#compiler' */
+/** @import { ArrowFunctionExpression, AssignmentExpression, Expression, FunctionDeclaration, FunctionExpression, Identifier, Node, Pattern, UpdateExpression } from 'estree' */
+/** @import { Binding } from '#compiler' */
 /** @import { ClientTransformState, ComponentClientTransformState, ComponentContext } from './types.js' */
 /** @import { Analysis } from '../../types.js' */
 /** @import { Scope } from '../../scope.js' */
 import * as b from '../../../utils/builders.js';
-import { extract_identifiers, is_simple_expression } from '../../../utils/ast.js';
+import { is_simple_expression } from '../../../utils/ast.js';
 import {
 	PROPS_IS_LAZY_INITIAL,
 	PROPS_IS_IMMUTABLE,
@@ -13,7 +13,8 @@ import {
 	PROPS_IS_BINDABLE
 } from '../../../../constants.js';
 import { dev } from '../../../state.js';
-import { get_value } from './visitors/shared/declarations.js';
+import { walk } from 'zimmerframe';
+import { validate_mutation } from './visitors/shared/utils.js';
 
 /**
  * @param {Binding} binding
@@ -110,6 +111,30 @@ function get_hoisted_params(node, context) {
 			}
 		}
 	}
+
+	if (dev) {
+		// this is a little hacky, but necessary for ownership validation
+		// to work inside hoisted event handlers
+
+		/**
+		 * @param {AssignmentExpression | UpdateExpression} node
+		 * @param {{ next: () => void, stop: () => void }} context
+		 */
+		function visit(node, { next, stop }) {
+			if (validate_mutation(node, /** @type {any} */ (context), node) !== node) {
+				params.push(b.id('$$ownership_validator'));
+				stop();
+			} else {
+				next();
+			}
+		}
+
+		walk(/** @type {Node} */ (node), null, {
+			AssignmentExpression: visit,
+			UpdateExpression: visit
+		});
+	}
+
 	return params;
 }
 
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/AssignmentExpression.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/AssignmentExpression.js
index 850cd83b15b6..4baa1c8e6ce5 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/AssignmentExpression.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/AssignmentExpression.js
@@ -7,9 +7,10 @@ import {
 	get_attribute_expression,
 	is_event_attribute
 } from '../../../../utils/ast.js';
-import { dev, is_ignored, locate_node } from '../../../../state.js';
+import { dev, locate_node } from '../../../../state.js';
 import { should_proxy } from '../utils.js';
 import { visit_assignment_expression } from '../../shared/assignments.js';
+import { validate_mutation } from './shared/utils.js';
 
 /**
  * @param {AssignmentExpression} node
@@ -20,9 +21,7 @@ export function AssignmentExpression(node, context) {
 		visit_assignment_expression(node, context, build_assignment) ?? context.next()
 	);
 
-	return is_ignored(node, 'ownership_invalid_mutation')
-		? b.call('$.skip_ownership_validation', b.thunk(expression))
-		: expression;
+	return validate_mutation(node, context, expression);
 }
 
 /**
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/ClassBody.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/ClassBody.js
index 24c20d7f947f..efc3c95c3c34 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/ClassBody.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/ClassBody.js
@@ -161,33 +161,6 @@ export function ClassBody(node, context) {
 		body.push(/** @type {MethodDefinition} **/ (context.visit(definition, child_state)));
 	}
 
-	if (dev && public_state.size > 0) {
-		// add an `[$.ADD_OWNER]` method so that a class with state fields can widen ownership
-		body.push(
-			b.method(
-				'method',
-				b.id('$.ADD_OWNER'),
-				[b.id('owner')],
-				[
-					b.stmt(
-						b.call(
-							'$.add_owner_to_class',
-							b.this,
-							b.id('owner'),
-							b.array(
-								Array.from(public_state).map(([name]) =>
-									b.thunk(b.call('$.get', b.member(b.this, b.private_id(name))))
-								)
-							),
-							is_ignored(node, 'ownership_invalid_binding') && b.true
-						)
-					)
-				],
-				true
-			)
-		);
-	}
-
 	return { ...node, body };
 }
 
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/UpdateExpression.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/UpdateExpression.js
index 13c1b4bc51e1..63c03b0eb6f2 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/UpdateExpression.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/UpdateExpression.js
@@ -1,8 +1,8 @@
 /** @import { AssignmentExpression, Expression, UpdateExpression } from 'estree' */
 /** @import { Context } from '../types' */
-import { is_ignored } from '../../../../state.js';
 import { object } from '../../../../utils/ast.js';
 import * as b from '../../../../utils/builders.js';
+import { validate_mutation } from './shared/utils.js';
 
 /**
  * @param {UpdateExpression} node
@@ -51,7 +51,5 @@ export function UpdateExpression(node, context) {
 		);
 	}
 
-	return is_ignored(node, 'ownership_invalid_mutation')
-		? b.call('$.skip_ownership_validation', b.thunk(update))
-		: update;
+	return validate_mutation(node, context, update);
 }
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/component.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/component.js
index 2bae4486dc58..2ea68e206e2e 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/component.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/component.js
@@ -179,19 +179,29 @@ export function build_component(node, component_name, context, anchor = context.
 		} else if (attribute.type === 'BindDirective') {
 			const expression = /** @type {Expression} */ (context.visit(attribute.expression));
 
-			if (dev && attribute.name !== 'this') {
-				binding_initializers.push(
-					b.stmt(
-						b.call(
-							b.id('$.add_owner_effect'),
-							expression.type === 'SequenceExpression'
-								? expression.expressions[0]
-								: b.thunk(expression),
-							b.id(component_name),
-							is_ignored(node, 'ownership_invalid_binding') && b.true
+			if (
+				dev &&
+				attribute.name !== 'this' &&
+				!is_ignored(node, 'ownership_invalid_binding') &&
+				// bind:x={() => x.y, y => x.y = y} will be handled by the assignment expression binding validation
+				attribute.expression.type !== 'SequenceExpression'
+			) {
+				const left = object(attribute.expression);
+				const binding = left && context.state.scope.get(left.name);
+
+				if (binding?.kind === 'bindable_prop' || binding?.kind === 'prop') {
+					context.state.analysis.needs_mutation_validation = true;
+					binding_initializers.push(
+						b.stmt(
+							b.call(
+								'$$ownership_validator.binding',
+								b.literal(binding.node.name),
+								b.id(component_name),
+								b.thunk(expression)
+							)
 						)
-					)
-				);
+					);
+				}
 			}
 
 			if (expression.type === 'SequenceExpression') {
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
index df6308d6316a..af6e56f70c81 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
@@ -1,13 +1,13 @@
-/** @import { Expression, ExpressionStatement, Identifier, MemberExpression, SequenceExpression, Statement, Super } from 'estree' */
+/** @import { AssignmentExpression, Expression, ExpressionStatement, Identifier, MemberExpression, SequenceExpression, Literal, Super, UpdateExpression } from 'estree' */
 /** @import { AST, ExpressionMetadata } from '#compiler' */
-/** @import { ComponentClientTransformState } from '../../types' */
+/** @import { ComponentClientTransformState, Context } from '../../types' */
 import { walk } from 'zimmerframe';
 import { object } from '../../../../../utils/ast.js';
 import * as b from '../../../../../utils/builders.js';
 import { sanitize_template_string } from '../../../../../utils/sanitize_template_string.js';
 import { regex_is_valid_identifier } from '../../../../patterns.js';
 import is_reference from 'is-reference';
-import { locator } from '../../../../../state.js';
+import { dev, is_ignored, locator } from '../../../../../state.js';
 import { create_derived } from '../../utils.js';
 
 /**
@@ -295,3 +295,60 @@ export function validate_binding(state, binding, expression) {
 		)
 	);
 }
+
+/**
+ * In dev mode validate mutations to props
+ * @param {AssignmentExpression | UpdateExpression} node
+ * @param {Context} context
+ * @param {Expression} expression
+ */
+export function validate_mutation(node, context, expression) {
+	let left = /** @type {Expression | Super} */ (
+		node.type === 'AssignmentExpression' ? node.left : node.argument
+	);
+
+	if (!dev || left.type !== 'MemberExpression' || is_ignored(node, 'ownership_invalid_mutation')) {
+		return expression;
+	}
+
+	const name = object(left);
+	if (!name) return expression;
+
+	const binding = context.state.scope.get(name.name);
+	if (binding?.kind !== 'prop' && binding?.kind !== 'bindable_prop') return expression;
+
+	const state = /** @type {ComponentClientTransformState} */ (context.state);
+	state.analysis.needs_mutation_validation = true;
+
+	/** @type {Array<Identifier | Literal>} */
+	const path = [];
+
+	while (left.type === 'MemberExpression') {
+		if (left.property.type === 'Literal') {
+			path.unshift(left.property);
+		} else if (left.property.type === 'Identifier') {
+			if (left.computed) {
+				path.unshift(left.property);
+			} else {
+				path.unshift(b.literal(left.property.name));
+			}
+		} else {
+			return expression;
+		}
+
+		left = left.object;
+	}
+
+	path.unshift(b.literal(name.name));
+
+	const loc = locator(/** @type {number} */ (left.start));
+
+	return b.call(
+		'$$ownership_validator.mutation',
+		b.literal(binding.prop_alias),
+		b.array(path),
+		expression,
+		loc && b.literal(loc.line),
+		loc && b.literal(loc.column)
+	);
+}
diff --git a/packages/svelte/src/compiler/phases/types.d.ts b/packages/svelte/src/compiler/phases/types.d.ts
index abe2b115de02..f09b88130305 100644
--- a/packages/svelte/src/compiler/phases/types.d.ts
+++ b/packages/svelte/src/compiler/phases/types.d.ts
@@ -53,6 +53,7 @@ export interface ComponentAnalysis extends Analysis {
 	uses_component_bindings: boolean;
 	uses_render_tags: boolean;
 	needs_context: boolean;
+	needs_mutation_validation: boolean;
 	needs_props: boolean;
 	/** Set to the first event directive (on:x) found on a DOM element in the code */
 	event_directive_node: AST.OnDirective | null;
diff --git a/packages/svelte/src/internal/client/constants.js b/packages/svelte/src/internal/client/constants.js
index 21377c1cc85f..7e5196c606b4 100644
--- a/packages/svelte/src/internal/client/constants.js
+++ b/packages/svelte/src/internal/client/constants.js
@@ -23,6 +23,5 @@ export const EFFECT_HAS_DERIVED = 1 << 20;
 export const EFFECT_IS_UPDATING = 1 << 21;
 
 export const STATE_SYMBOL = Symbol('$state');
-export const STATE_SYMBOL_METADATA = Symbol('$state metadata');
 export const LEGACY_PROPS = Symbol('legacy props');
 export const LOADING_ATTR_SYMBOL = Symbol('');
diff --git a/packages/svelte/src/internal/client/context.js b/packages/svelte/src/internal/client/context.js
index bfca9d5e6a72..7a2fdd0edb6d 100644
--- a/packages/svelte/src/internal/client/context.js
+++ b/packages/svelte/src/internal/client/context.js
@@ -1,7 +1,6 @@
 /** @import { ComponentContext } from '#client' */
 
 import { DEV } from 'esm-env';
-import { add_owner } from './dev/ownership.js';
 import { lifecycle_outside_component } from '../shared/errors.js';
 import { source } from './reactivity/sources.js';
 import {
@@ -67,15 +66,6 @@ export function getContext(key) {
  */
 export function setContext(key, context) {
 	const context_map = get_or_init_context_map('setContext');
-
-	if (DEV) {
-		// When state is put into context, we treat as if it's global from now on.
-		// We do for performance reasons (it's for example very expensive to call
-		// getContext on a big object many times when part of a list component)
-		// and danger of false positives.
-		untrack(() => add_owner(context, null, true));
-	}
-
 	context_map.set(key, context);
 	return context;
 }
diff --git a/packages/svelte/src/internal/client/dev/ownership.js b/packages/svelte/src/internal/client/dev/ownership.js
index 62119b36dbd6..6c40a744dfc5 100644
--- a/packages/svelte/src/internal/client/dev/ownership.js
+++ b/packages/svelte/src/internal/client/dev/ownership.js
@@ -1,12 +1,11 @@
-/** @import { ProxyMetadata } from '#client' */
 /** @typedef {{ file: string, line: number, column: number }} Location */
 
-import { STATE_SYMBOL_METADATA } from '../constants.js';
-import { render_effect, user_pre_effect } from '../reactivity/effects.js';
-import { dev_current_component_function } from '../context.js';
-import { get_prototype_of } from '../../shared/utils.js';
+import { get_descriptor } from '../../shared/utils.js';
+import { LEGACY_PROPS, STATE_SYMBOL } from '../constants.js';
+import { FILENAME } from '../../../constants.js';
+import { component_context } from '../context.js';
 import * as w from '../warnings.js';
-import { FILENAME, UNINITIALIZED } from '../../../constants.js';
+import { sanitize_location } from '../../../utils.js';
 
 /** @type {Record<string, Array<{ start: Location, end: Location, component: Function }>>} */
 const boundaries = {};
@@ -71,8 +70,6 @@ export function get_component() {
 	return null;
 }
 
-export const ADD_OWNER = Symbol('ADD_OWNER');
-
 /**
  * Together with `mark_module_end`, this function establishes the boundaries of a `.svelte` file,
  * such that subsequent calls to `get_component` can tell us which component is responsible
@@ -108,197 +105,69 @@ export function mark_module_end(component) {
 }
 
 /**
- * @param {any} object
- * @param {any | null} owner
- * @param {boolean} [global]
- * @param {boolean} [skip_warning]
+ * Sets up a validator that
+ * - traverses the path of a prop to find out if it is allowed to be mutated
+ * - checks that the binding chain is not interrupted
+ * @param {Record<string, any>} props
  */
-export function add_owner(object, owner, global = false, skip_warning = false) {
-	if (object && !global) {
-		const component = dev_current_component_function;
-		const metadata = object[STATE_SYMBOL_METADATA];
-		if (metadata && !has_owner(metadata, component)) {
-			let original = get_owner(metadata);
-
-			if (owner && owner[FILENAME] !== component[FILENAME] && !skip_warning) {
-				w.ownership_invalid_binding(component[FILENAME], owner[FILENAME], original[FILENAME]);
+export function create_ownership_validator(props) {
+	const component = component_context?.function;
+	const parent = component_context?.p?.function;
+
+	return {
+		/**
+		 * @param {string} prop
+		 * @param {any[]} path
+		 * @param {any} result
+		 * @param {number} line
+		 * @param {number} column
+		 */
+		mutation: (prop, path, result, line, column) => {
+			const name = path[0];
+			if (is_bound(props, name) || !parent) {
+				return result;
 			}
-		}
-	}
 
-	add_owner_to_object(object, owner, new Set());
-}
-
-/**
- * @param {() => unknown} get_object
- * @param {any} Component
- * @param {boolean} [skip_warning]
- */
-export function add_owner_effect(get_object, Component, skip_warning = false) {
-	user_pre_effect(() => {
-		add_owner(get_object(), Component, false, skip_warning);
-	});
-}
-
-/**
- * @param {any} _this
- * @param {Function} owner
- * @param {Array<() => any>} getters
- * @param {boolean} skip_warning
- */
-export function add_owner_to_class(_this, owner, getters, skip_warning) {
-	_this[ADD_OWNER].current ||= getters.map(() => UNINITIALIZED);
-
-	for (let i = 0; i < getters.length; i += 1) {
-		const current = getters[i]();
-		// For performance reasons we only re-add the owner if the state has changed
-		if (current !== _this[ADD_OWNER][i]) {
-			_this[ADD_OWNER].current[i] = current;
-			add_owner(current, owner, false, skip_warning);
-		}
-	}
-}
-
-/**
- * @param {ProxyMetadata | null} from
- * @param {ProxyMetadata} to
- */
-export function widen_ownership(from, to) {
-	if (to.owners === null) {
-		return;
-	}
-
-	while (from) {
-		if (from.owners === null) {
-			to.owners = null;
-			break;
-		}
-
-		for (const owner of from.owners) {
-			to.owners.add(owner);
-		}
-
-		from = from.parent;
-	}
-}
-
-/**
- * @param {any} object
- * @param {Function | null} owner If `null`, then the object is globally owned and will not be checked
- * @param {Set<any>} seen
- */
-function add_owner_to_object(object, owner, seen) {
-	const metadata = /** @type {ProxyMetadata} */ (object?.[STATE_SYMBOL_METADATA]);
+			let value = props[name];
 
-	if (metadata) {
-		// this is a state proxy, add owner directly, if not globally shared
-		if ('owners' in metadata && metadata.owners != null) {
-			if (owner) {
-				metadata.owners.add(owner);
-			} else {
-				metadata.owners = null;
+			for (let i = 1; i < path.length - 1; i++) {
+				if (!value?.[STATE_SYMBOL]) {
+					return result;
+				}
+				value = value[path[i]];
 			}
-		}
-	} else if (object && typeof object === 'object') {
-		if (seen.has(object)) return;
-		seen.add(object);
-		if (ADD_OWNER in object && object[ADD_OWNER]) {
-			// this is a class with state fields. we put this in a render effect
-			// so that if state is replaced (e.g. `instance.name = { first, last }`)
-			// the new state is also co-owned by the caller of `getContext`
-			render_effect(() => {
-				object[ADD_OWNER](owner);
-			});
-		} else {
-			var proto = get_prototype_of(object);
 
-			if (proto === Object.prototype) {
-				// recurse until we find a state proxy
-				for (const key in object) {
-					if (Object.getOwnPropertyDescriptor(object, key)?.get) {
-						// Similar to the class case; the getter could update with a new state
-						let current = UNINITIALIZED;
-						render_effect(() => {
-							const next = object[key];
-							if (current !== next) {
-								current = next;
-								add_owner_to_object(next, owner, seen);
-							}
-						});
-					} else {
-						add_owner_to_object(object[key], owner, seen);
-					}
-				}
-			} else if (proto === Array.prototype) {
-				// recurse until we find a state proxy
-				for (let i = 0; i < object.length; i += 1) {
-					add_owner_to_object(object[i], owner, seen);
-				}
+			const location = sanitize_location(`${component[FILENAME]}:${line}:${column}`);
+
+			w.ownership_invalid_mutation(name, location, prop, parent[FILENAME]);
+
+			return result;
+		},
+		/**
+		 * @param {any} key
+		 * @param {any} child_component
+		 * @param {() => any} value
+		 */
+		binding: (key, child_component, value) => {
+			if (!is_bound(props, key) && parent && value()?.[STATE_SYMBOL]) {
+				w.ownership_invalid_binding(
+					component[FILENAME],
+					key,
+					child_component[FILENAME],
+					parent[FILENAME]
+				);
 			}
 		}
-	}
+	};
 }
 
 /**
- * @param {ProxyMetadata} metadata
- * @param {Function} component
- * @returns {boolean}
+ * @param {Record<string, any>} props
+ * @param {string} prop_name
  */
-function has_owner(metadata, component) {
-	if (metadata.owners === null) {
-		return true;
-	}
-
-	return (
-		metadata.owners.has(component) ||
-		// This helps avoid false positives when using HMR, where the component function is replaced
-		(FILENAME in component &&
-			[...metadata.owners].some(
-				(owner) => /** @type {any} */ (owner)[FILENAME] === component[FILENAME]
-			)) ||
-		(metadata.parent !== null && has_owner(metadata.parent, component))
-	);
-}
-
-/**
- * @param {ProxyMetadata} metadata
- * @returns {any}
- */
-function get_owner(metadata) {
-	return (
-		metadata?.owners?.values().next().value ??
-		get_owner(/** @type {ProxyMetadata} */ (metadata.parent))
-	);
-}
-
-let skip = false;
-
-/**
- * @param {() => any} fn
- */
-export function skip_ownership_validation(fn) {
-	skip = true;
-	fn();
-	skip = false;
-}
-
-/**
- * @param {ProxyMetadata} metadata
- */
-export function check_ownership(metadata) {
-	if (skip) return;
-
-	const component = get_component();
-
-	if (component && !has_owner(metadata, component)) {
-		let original = get_owner(metadata);
-
-		// @ts-expect-error
-		if (original[FILENAME] !== component[FILENAME]) {
-			// @ts-expect-error
-			w.ownership_invalid_mutation(component[FILENAME], original[FILENAME]);
-		} else {
-			w.ownership_invalid_mutation();
-		}
-	}
+function is_bound(props, prop_name) {
+	// Can be the case when someone does `mount(Component, props)` with `let props = $state({...})`
+	// or `createClassComponent(Component, props)`
+	const is_entry_props = STATE_SYMBOL in props || LEGACY_PROPS in props;
+	return !!get_descriptor(props, prop_name)?.set || (is_entry_props && prop_name in props);
 }
diff --git a/packages/svelte/src/internal/client/index.js b/packages/svelte/src/internal/client/index.js
index a5f93e8b171b..7eed8a744afa 100644
--- a/packages/svelte/src/internal/client/index.js
+++ b/packages/svelte/src/internal/client/index.js
@@ -4,15 +4,7 @@ export { assign, assign_and, assign_or, assign_nullish } from './dev/assign.js';
 export { cleanup_styles } from './dev/css.js';
 export { add_locations } from './dev/elements.js';
 export { hmr } from './dev/hmr.js';
-export {
-	ADD_OWNER,
-	add_owner,
-	mark_module_start,
-	mark_module_end,
-	add_owner_effect,
-	add_owner_to_class,
-	skip_ownership_validation
-} from './dev/ownership.js';
+export { mark_module_start, mark_module_end, create_ownership_validator } from './dev/ownership.js';
 export { check_target, legacy_api } from './dev/legacy.js';
 export { trace } from './dev/tracing.js';
 export { inspect } from './dev/inspect.js';
diff --git a/packages/svelte/src/internal/client/proxy.js b/packages/svelte/src/internal/client/proxy.js
index fab271c91652..5e0aa3dbc35f 100644
--- a/packages/svelte/src/internal/client/proxy.js
+++ b/packages/svelte/src/internal/client/proxy.js
@@ -1,7 +1,6 @@
-/** @import { ProxyMetadata, Source } from '#client' */
+/** @import { Source } from '#client' */
 import { DEV } from 'esm-env';
 import { get, active_effect, active_reaction, set_active_reaction } from './runtime.js';
-import { component_context } from './context.js';
 import {
 	array_prototype,
 	get_descriptor,
@@ -9,24 +8,19 @@ import {
 	is_array,
 	object_prototype
 } from '../shared/utils.js';
-import { check_ownership, widen_ownership } from './dev/ownership.js';
 import { state as source, set } from './reactivity/sources.js';
-import { STATE_SYMBOL, STATE_SYMBOL_METADATA } from './constants.js';
+import { STATE_SYMBOL } from './constants.js';
 import { UNINITIALIZED } from '../../constants.js';
 import * as e from './errors.js';
 import { get_stack } from './dev/tracing.js';
 import { tracing_mode_flag } from '../flags/index.js';
 
-/** @type {ProxyMetadata | null} */
-var parent_metadata = null;
-
 /**
  * @template T
  * @param {T} value
- * @param {Source<T>} [prev] dev mode only
  * @returns {T}
  */
-export function proxy(value, prev) {
+export function proxy(value) {
 	// if non-proxyable, or is already a proxy, return `value`
 	if (typeof value !== 'object' || value === null || STATE_SYMBOL in value) {
 		return value;
@@ -55,16 +49,7 @@ export function proxy(value, prev) {
 		set_active_reaction(reaction);
 
 		/** @type {T} */
-		var result;
-
-		if (DEV) {
-			var previous_metadata = parent_metadata;
-			parent_metadata = metadata;
-			result = fn();
-			parent_metadata = previous_metadata;
-		} else {
-			result = fn();
-		}
+		var result = fn();
 
 		set_active_reaction(previous_reaction);
 		return result;
@@ -76,31 +61,6 @@ export function proxy(value, prev) {
 		sources.set('length', source(/** @type {any[]} */ (value).length, stack));
 	}
 
-	/** @type {ProxyMetadata} */
-	var metadata;
-
-	if (DEV) {
-		metadata = {
-			parent: parent_metadata,
-			owners: null
-		};
-
-		if (prev) {
-			// Reuse owners from previous state; necessary because reassignment is not guaranteed to have correct component context.
-			// If no previous proxy exists we play it safe and assume ownerless state
-			// @ts-expect-error
-			const prev_owners = prev.v?.[STATE_SYMBOL_METADATA]?.owners;
-			metadata.owners = prev_owners ? new Set(prev_owners) : null;
-		} else {
-			metadata.owners =
-				parent_metadata === null
-					? component_context !== null
-						? new Set([component_context.function])
-						: null
-					: new Set();
-		}
-	}
-
 	return new Proxy(/** @type {any} */ (value), {
 		defineProperty(_, prop, descriptor) {
 			if (
@@ -160,10 +120,6 @@ export function proxy(value, prev) {
 		},
 
 		get(target, prop, receiver) {
-			if (DEV && prop === STATE_SYMBOL_METADATA) {
-				return metadata;
-			}
-
 			if (prop === STATE_SYMBOL) {
 				return value;
 			}
@@ -179,22 +135,6 @@ export function proxy(value, prev) {
 
 			if (s !== undefined) {
 				var v = get(s);
-
-				// In case of something like `foo = bar.map(...)`, foo would have ownership
-				// of the array itself, while the individual items would have ownership
-				// of the component that created bar. That means if we later do `foo[0].baz = 42`,
-				// we could get a false-positive ownership violation, since the two proxies
-				// are not connected to each other via the parent metadata relationship.
-				// For this reason, we need to widen the ownership of the children
-				// upon access when we detect they are not connected.
-				if (DEV) {
-					/** @type {ProxyMetadata | undefined} */
-					var prop_metadata = v?.[STATE_SYMBOL_METADATA];
-					if (prop_metadata && prop_metadata?.parent !== metadata) {
-						widen_ownership(metadata, prop_metadata);
-					}
-				}
-
 				return v === UNINITIALIZED ? undefined : v;
 			}
 
@@ -225,10 +165,6 @@ export function proxy(value, prev) {
 		},
 
 		has(target, prop) {
-			if (DEV && prop === STATE_SYMBOL_METADATA) {
-				return true;
-			}
-
 			if (prop === STATE_SYMBOL) {
 				return true;
 			}
@@ -295,15 +231,6 @@ export function proxy(value, prev) {
 				);
 			}
 
-			if (DEV) {
-				/** @type {ProxyMetadata | undefined} */
-				var prop_metadata = value?.[STATE_SYMBOL_METADATA];
-				if (prop_metadata && prop_metadata?.parent !== metadata) {
-					widen_ownership(metadata, prop_metadata);
-				}
-				check_ownership(metadata);
-			}
-
 			var descriptor = Reflect.getOwnPropertyDescriptor(target, prop);
 
 			// Set the new value before updating any signals so that any listeners get the new value
diff --git a/packages/svelte/src/internal/client/reactivity/sources.js b/packages/svelte/src/internal/client/reactivity/sources.js
index e4834902fe3f..aa65d5354ac7 100644
--- a/packages/svelte/src/internal/client/reactivity/sources.js
+++ b/packages/svelte/src/internal/client/reactivity/sources.js
@@ -139,7 +139,7 @@ export function set(source, value, should_proxy = false) {
 		e.state_unsafe_mutation();
 	}
 
-	let new_value = should_proxy ? proxy(value, source) : value;
+	let new_value = should_proxy ? proxy(value) : value;
 
 	return internal_set(source, new_value);
 }
diff --git a/packages/svelte/src/internal/client/types.d.ts b/packages/svelte/src/internal/client/types.d.ts
index 0c260a0a9ffa..b46bdf201341 100644
--- a/packages/svelte/src/internal/client/types.d.ts
+++ b/packages/svelte/src/internal/client/types.d.ts
@@ -179,14 +179,6 @@ export type TaskCallback = (now: number) => boolean | void;
 
 export type TaskEntry = { c: TaskCallback; f: () => void };
 
-/** Dev-only */
-export interface ProxyMetadata {
-	/** The components that 'own' this state, if any. `null` means no owners, i.e. everyone can mutate this state. */
-	owners: null | Set<Function>;
-	/** The parent metadata object */
-	parent: null | ProxyMetadata;
-}
-
 export type ProxyStateObject<T = Record<string | symbol, any>> = T & {
 	[STATE_SYMBOL]: T;
 };
diff --git a/packages/svelte/src/internal/client/warnings.js b/packages/svelte/src/internal/client/warnings.js
index 250c6eca2fe9..c84b487e280d 100644
--- a/packages/svelte/src/internal/client/warnings.js
+++ b/packages/svelte/src/internal/client/warnings.js
@@ -129,27 +129,30 @@ export function lifecycle_double_unmount() {
 }
 
 /**
- * %parent% passed a value to %child% with `bind:`, but the value is owned by %owner%. Consider creating a binding between %owner% and %parent%
+ * %parent% passed property `%prop%` to %child% with `bind:`, but its parent component %owner% did not declare `%prop%` as a binding. Consider creating a binding between %owner% and %parent% (e.g. `bind:%prop%={...}` instead of `%prop%={...}`)
  * @param {string} parent
+ * @param {string} prop
  * @param {string} child
  * @param {string} owner
  */
-export function ownership_invalid_binding(parent, child, owner) {
+export function ownership_invalid_binding(parent, prop, child, owner) {
 	if (DEV) {
-		console.warn(`%c[svelte] ownership_invalid_binding\n%c${parent} passed a value to ${child} with \`bind:\`, but the value is owned by ${owner}. Consider creating a binding between ${owner} and ${parent}\nhttps://svelte.dev/e/ownership_invalid_binding`, bold, normal);
+		console.warn(`%c[svelte] ownership_invalid_binding\n%c${parent} passed property \`${prop}\` to ${child} with \`bind:\`, but its parent component ${owner} did not declare \`${prop}\` as a binding. Consider creating a binding between ${owner} and ${parent} (e.g. \`bind:${prop}={...}\` instead of \`${prop}={...}\`)\nhttps://svelte.dev/e/ownership_invalid_binding`, bold, normal);
 	} else {
 		console.warn(`https://svelte.dev/e/ownership_invalid_binding`);
 	}
 }
 
 /**
- * %component% mutated a value owned by %owner%. This is strongly discouraged. Consider passing values to child components with `bind:`, or use a callback instead
- * @param {string | undefined | null} [component]
- * @param {string | undefined | null} [owner]
+ * Mutating unbound props (`%name%`, at %location%) is strongly discouraged. Consider using `bind:%prop%={...}` in %parent% (or using a callback) instead
+ * @param {string} name
+ * @param {string} location
+ * @param {string} prop
+ * @param {string} parent
  */
-export function ownership_invalid_mutation(component, owner) {
+export function ownership_invalid_mutation(name, location, prop, parent) {
 	if (DEV) {
-		console.warn(`%c[svelte] ownership_invalid_mutation\n%c${component ? `${component} mutated a value owned by ${owner}. This is strongly discouraged. Consider passing values to child components with \`bind:\`, or use a callback instead` : 'Mutating a value outside the component that created it is strongly discouraged. Consider passing values to child components with `bind:`, or use a callback instead'}\nhttps://svelte.dev/e/ownership_invalid_mutation`, bold, normal);
+		console.warn(`%c[svelte] ownership_invalid_mutation\n%cMutating unbound props (\`${name}\`, at ${location}) is strongly discouraged. Consider using \`bind:${prop}={...}\` in ${parent} (or using a callback) instead\nhttps://svelte.dev/e/ownership_invalid_mutation`, bold, normal);
 	} else {
 		console.warn(`https://svelte.dev/e/ownership_invalid_mutation`);
 	}
diff --git a/packages/svelte/src/utils.js b/packages/svelte/src/utils.js
index d4d106d56deb..ada318e85ac7 100644
--- a/packages/svelte/src/utils.js
+++ b/packages/svelte/src/utils.js
@@ -465,8 +465,10 @@ export function is_raw_text_element(name) {
 
 /**
  * Prevent devtools trying to make `location` a clickable link by inserting a zero-width space
- * @param {string | undefined} location
+ * @template {string | undefined} T
+ * @param {T} location
+ * @returns {T};
  */
 export function sanitize_location(location) {
-	return location?.replace(/\//g, '/\u200b');
+	return /** @type {T} */ (location?.replace(/\//g, '/\u200b'));
 }
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-discouraged/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-discouraged/_config.js
index 62c696124285..84526610260d 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-discouraged/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-discouraged/_config.js
@@ -10,7 +10,7 @@ export default test({
 
 	test({ assert, target, warnings }) {
 		const warning =
-			'Counter.svelte mutated a value owned by main.svelte. This is strongly discouraged. Consider passing values to child components with `bind:`, or use a callback instead';
+			'Mutating unbound props (`object`, at Counter.svelte:5:23) is strongly discouraged. Consider using `bind:object={...}` in main.svelte (or using a callback) instead';
 		const [btn1, btn2] = target.querySelectorAll('button');
 
 		btn1.click();
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-global-2/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-global-2/_config.js
deleted file mode 100644
index b4864154c39a..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-global-2/_config.js
+++ /dev/null
@@ -1,11 +0,0 @@
-import { test } from '../../test';
-
-export default test({
-	compileOptions: {
-		dev: true
-	},
-
-	async test({ assert, warnings }) {
-		assert.deepEqual(warnings, []);
-	}
-});
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-global-2/child.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-global-2/child.svelte
deleted file mode 100644
index 13de75364752..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-global-2/child.svelte
+++ /dev/null
@@ -1,18 +0,0 @@
-<script module>
-	let toast1 = $state();
-	let toast2 = $state({});
-
-	export async function show_toast() {
-		toast1 = {
-			message: 'foo',
-			show: true
-		};
-		toast1.show = false;
-
-		toast2 = {
-			message: 'foo',
-			show: true
-		};
-		toast2.show = false;
-	}
-</script>
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-global-2/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-global-2/main.svelte
deleted file mode 100644
index 8a6922e9e250..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-global-2/main.svelte
+++ /dev/null
@@ -1,5 +0,0 @@
-<script>
-	import { show_toast } from "./child.svelte";
-
-	show_toast();
-</script>
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-1/_config.js
similarity index 74%
rename from packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/_config.js
rename to packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-1/_config.js
index c07b9ce129dc..96b18d1854c8 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-1/_config.js
@@ -8,7 +8,7 @@ let warn;
 let warnings = [];
 
 export default test({
-	html: `<button>clicks: 0</button>`,
+	html: `<button>[]</button>`,
 
 	compileOptions: {
 		dev: true
@@ -34,8 +34,8 @@ export default test({
 			btn?.click();
 		});
 
-		assert.htmlEqual(target.innerHTML, `<button>clicks: 1</button>`);
+		assert.htmlEqual(target.innerHTML, `<button>[foo]</button>`);
 
-		assert.deepEqual(warnings, []);
+		assert.deepEqual(warnings, [], 'expected getContext to have widened ownership');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-1/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-1/main.svelte
new file mode 100644
index 000000000000..2dd7cab141d6
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-1/main.svelte
@@ -0,0 +1,9 @@
+<script>
+	import { setContext } from 'svelte';
+	import Sub from './sub.svelte';
+
+	let list = $state([]);
+	setContext('list', list);
+</script>
+
+<Sub />
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/sub.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-1/sub.svelte
similarity index 100%
rename from packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/sub.svelte
rename to packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-1/sub.svelte
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/_config.js
index c07b9ce129dc..66f1726a2aef 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/_config.js
@@ -1,41 +1,24 @@
 import { flushSync } from 'svelte';
 import { test } from '../../test';
 
-/** @type {typeof console.warn} */
-let warn;
-
-/** @type {any[]} */
-let warnings = [];
-
 export default test({
-	html: `<button>clicks: 0</button>`,
-
 	compileOptions: {
 		dev: true
 	},
 
-	before_test: () => {
-		warn = console.warn;
-
-		console.warn = (...args) => {
-			warnings.push(...args);
-		};
-	},
+	test({ assert, target, warnings }) {
+		const [btn1, btn2] = target.querySelectorAll('button');
 
-	after_test: () => {
-		console.warn = warn;
-		warnings = [];
-	},
+		flushSync(() => {
+			btn1.click();
+		});
 
-	test({ assert, target }) {
-		const btn = target.querySelector('button');
+		assert.deepEqual(warnings.length, 0);
 
 		flushSync(() => {
-			btn?.click();
+			btn2.click();
 		});
 
-		assert.htmlEqual(target.innerHTML, `<button>clicks: 1</button>`);
-
-		assert.deepEqual(warnings, []);
+		assert.deepEqual(warnings.length, 1);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/main.svelte
index ad450a937e40..0be7e434e475 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/main.svelte
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/main.svelte
@@ -1,9 +1,8 @@
-<script>
-	import { global } from './state.svelte.js';
+<script lang="ts">
+	import Sub from './sub.svelte';
+	import { create_my_state } from './state.svelte';
 
-	global.a = { b: 0 };
+	const myState = create_my_state();
 </script>
 
-<button onclick={() => global.a.b += 1}>
-	clicks: {global.a.b}
-</button>
+<Sub count={myState.my_state} inc={myState.inc} />
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/state.svelte.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/state.svelte.js
index 3e7a68cf97d8..2906b9bce52b 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/state.svelte.js
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/state.svelte.js
@@ -1 +1,14 @@
-export let global = $state({});
+export function create_my_state() {
+	const my_state = $state({
+		a: 0
+	});
+
+	function inc() {
+		my_state.a++;
+	}
+
+	return {
+		my_state,
+		inc
+	};
+}
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/sub.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/sub.svelte
similarity index 100%
rename from packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/sub.svelte
rename to packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-2/sub.svelte
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-7/Child.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/Child.svelte
similarity index 100%
rename from packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-7/Child.svelte
rename to packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/Child.svelte
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/_config.js
index 96b18d1854c8..ab7327ab8b82 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/_config.js
@@ -1,41 +1,24 @@
 import { flushSync } from 'svelte';
 import { test } from '../../test';
 
-/** @type {typeof console.warn} */
-let warn;
-
-/** @type {any[]} */
-let warnings = [];
-
 export default test({
-	html: `<button>[]</button>`,
-
 	compileOptions: {
 		dev: true
 	},
 
-	before_test: () => {
-		warn = console.warn;
-
-		console.warn = (...args) => {
-			warnings.push(...args);
-		};
-	},
+	async test({ assert, target, warnings }) {
+		const [btn1, btn2] = target.querySelectorAll('button');
 
-	after_test: () => {
-		console.warn = warn;
-		warnings = [];
-	},
+		flushSync(() => {
+			btn1.click();
+		});
 
-	test({ assert, target }) {
-		const btn = target.querySelector('button');
+		assert.deepEqual(warnings.length, 0);
 
 		flushSync(() => {
-			btn?.click();
+			btn2.click();
 		});
 
-		assert.htmlEqual(target.innerHTML, `<button>[foo]</button>`);
-
-		assert.deepEqual(warnings, [], 'expected getContext to have widened ownership');
+		assert.deepEqual(warnings.length, 1);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/main.svelte
index 2dd7cab141d6..8e8343790b1b 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/main.svelte
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-3/main.svelte
@@ -1,9 +1,13 @@
 <script>
-	import { setContext } from 'svelte';
-	import Sub from './sub.svelte';
+	import Child from './Child.svelte';
 
-	let list = $state([]);
-	setContext('list', list);
+	let items = $state([{ id: "test", name: "this is a test"}, { id:"test2", name: "this is a second test"}]);
+	let found = $state();
+
+	function onclick() {
+		found = items.find(c => c.id === 'test2');
+	}
 </script>
 
-<Sub />
+<button {onclick}>First click here</button>
+<Child item={found} />
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/_config.js
deleted file mode 100644
index aeb3740dfe71..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/_config.js
+++ /dev/null
@@ -1,37 +0,0 @@
-import { flushSync } from 'svelte';
-import { test } from '../../test';
-
-/** @type {typeof console.warn} */
-let warn;
-
-/** @type {any[]} */
-let warnings = [];
-
-export default test({
-	compileOptions: {
-		dev: true
-	},
-
-	before_test: () => {
-		warn = console.warn;
-
-		console.warn = (...args) => {
-			warnings.push(...args);
-		};
-	},
-
-	after_test: () => {
-		console.warn = warn;
-		warnings = [];
-	},
-
-	test({ assert, target }) {
-		const btn = target.querySelector('button');
-
-		flushSync(() => {
-			btn?.click();
-		});
-
-		assert.deepEqual(warnings, []);
-	}
-});
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/main.svelte
deleted file mode 100644
index 2d40c13949a6..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/main.svelte
+++ /dev/null
@@ -1,11 +0,0 @@
-<script>
-	import { global } from './state.svelte.js';
-	import Sub from './sub.svelte';
-</script>
-
-<Sub />
-<!-- it's important _NOT_ to read global.a.b in the template,
-     else the proxy would set up the structure with its own component context already -->
-<button onclick={() => global.increment_a_b()}>
-	click me
-</button>
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/state.svelte.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/state.svelte.js
deleted file mode 100644
index 40790591712c..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/state.svelte.js
+++ /dev/null
@@ -1,13 +0,0 @@
-class Global {
-	state = $state({});
-
-	add_a(a) {
-		this.state.a = a;
-	}
-
-	increment_a_b() {
-		this.state.a.b++;
-	}
-}
-
-export const global = new Global();
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/sub.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/sub.svelte
deleted file mode 100644
index 044904aa187e..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-4/sub.svelte
+++ /dev/null
@@ -1,8 +0,0 @@
-<script>
-	import { global } from "./state.svelte";
-    
-	// The real world use case would be someone manipulating state locally, for example form state,
-	// and then push the values to a global state for everyone else to see / possibly mutate.
-	const local_soon_global = $state({ b: 0 });
-	global.add_a(local_soon_global);
-</script>
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/_config.js
deleted file mode 100644
index 66f1726a2aef..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/_config.js
+++ /dev/null
@@ -1,24 +0,0 @@
-import { flushSync } from 'svelte';
-import { test } from '../../test';
-
-export default test({
-	compileOptions: {
-		dev: true
-	},
-
-	test({ assert, target, warnings }) {
-		const [btn1, btn2] = target.querySelectorAll('button');
-
-		flushSync(() => {
-			btn1.click();
-		});
-
-		assert.deepEqual(warnings.length, 0);
-
-		flushSync(() => {
-			btn2.click();
-		});
-
-		assert.deepEqual(warnings.length, 1);
-	}
-});
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/main.svelte
deleted file mode 100644
index 0be7e434e475..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/main.svelte
+++ /dev/null
@@ -1,8 +0,0 @@
-<script lang="ts">
-	import Sub from './sub.svelte';
-	import { create_my_state } from './state.svelte';
-
-	const myState = create_my_state();
-</script>
-
-<Sub count={myState.my_state} inc={myState.inc} />
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/state.svelte.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/state.svelte.js
deleted file mode 100644
index 2906b9bce52b..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-5/state.svelte.js
+++ /dev/null
@@ -1,14 +0,0 @@
-export function create_my_state() {
-	const my_state = $state({
-		a: 0
-	});
-
-	function inc() {
-		my_state.a++;
-	}
-
-	return {
-		my_state,
-		inc
-	};
-}
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-6/Child.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-6/Child.svelte
deleted file mode 100644
index aa31fd7606dd..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-6/Child.svelte
+++ /dev/null
@@ -1,9 +0,0 @@
-<script>
-	import { getContext } from 'svelte';
-
-	const foo = getContext('foo')
-</script>
-
-<button onclick={() => {
-	foo.person.name.last = 'T';
-}}>mutate</button>
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-6/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-6/_config.js
deleted file mode 100644
index cc9ea715f0aa..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-6/_config.js
+++ /dev/null
@@ -1,37 +0,0 @@
-import { flushSync } from 'svelte';
-import { test } from '../../test';
-
-/** @type {typeof console.warn} */
-let warn;
-
-/** @type {any[]} */
-let warnings = [];
-
-export default test({
-	compileOptions: {
-		dev: true
-	},
-
-	before_test: () => {
-		warn = console.warn;
-
-		console.warn = (...args) => {
-			warnings.push(...args);
-		};
-	},
-
-	after_test: () => {
-		console.warn = warn;
-		warnings = [];
-	},
-
-	async test({ assert, target }) {
-		const btn = target.querySelector('button');
-
-		flushSync(() => {
-			btn?.click();
-		});
-
-		assert.deepEqual(warnings.length, 0);
-	}
-});
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-6/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-6/main.svelte
deleted file mode 100644
index 92d7dbd2db6c..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-6/main.svelte
+++ /dev/null
@@ -1,17 +0,0 @@
-<script>
-	import { setContext } from 'svelte';
-	import Child from './Child.svelte';
-
-	class Person {
-		name = $state({
-			first: 'Mr',
-			last: 'Bean'
-		});
-	}
-
-	setContext('foo', {
-		person: new Person()
-	});
-</script>
-
-<Child />
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-7/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-7/_config.js
deleted file mode 100644
index ab7327ab8b82..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-7/_config.js
+++ /dev/null
@@ -1,24 +0,0 @@
-import { flushSync } from 'svelte';
-import { test } from '../../test';
-
-export default test({
-	compileOptions: {
-		dev: true
-	},
-
-	async test({ assert, target, warnings }) {
-		const [btn1, btn2] = target.querySelectorAll('button');
-
-		flushSync(() => {
-			btn1.click();
-		});
-
-		assert.deepEqual(warnings.length, 0);
-
-		flushSync(() => {
-			btn2.click();
-		});
-
-		assert.deepEqual(warnings.length, 1);
-	}
-});
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-7/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-7/main.svelte
deleted file mode 100644
index 8e8343790b1b..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner-7/main.svelte
+++ /dev/null
@@ -1,13 +0,0 @@
-<script>
-	import Child from './Child.svelte';
-
-	let items = $state([{ id: "test", name: "this is a test"}, { id:"test2", name: "this is a second test"}]);
-	let found = $state();
-
-	function onclick() {
-		found = items.find(c => c.id === 'test2');
-	}
-</script>
-
-<button {onclick}>First click here</button>
-<Child item={found} />
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/Counter.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/Counter.svelte
deleted file mode 100644
index ffe6ef75c4ed..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/Counter.svelte
+++ /dev/null
@@ -1,7 +0,0 @@
-<script>
-	import { global } from './state.svelte.js';
-</script>
-
-<button onclick={() => global.object.count += 1}>
-	clicks: {global.object.count}
-</button>
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/main.svelte
deleted file mode 100644
index 5f1c7461f636..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/main.svelte
+++ /dev/null
@@ -1,9 +0,0 @@
-<script>
-	import Counter from './Counter.svelte';
-	import { global } from './state.svelte.js';
-
-	let object = $state({ count: 0 });
-	global.object = object;
-</script>
-
-<Counter />
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/state.svelte.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/state.svelte.js
deleted file mode 100644
index 6881c2faf66b..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-inherited-owner/state.svelte.js
+++ /dev/null
@@ -1,3 +0,0 @@
-export let global = $state({
-	object: { count: -1 }
-});
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-2/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-2/_config.js
index 87474a05cc33..39fa80c55a4e 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-2/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-2/_config.js
@@ -8,6 +8,6 @@ export default test({
 	},
 
 	warnings: [
-		'Intermediate.svelte passed a value to Counter.svelte with `bind:`, but the value is owned by main.svelte. Consider creating a binding between main.svelte and Intermediate.svelte'
+		'Intermediate.svelte passed property `object` to Counter.svelte with `bind:`, but its parent component main.svelte did not declare `object` as a binding. Consider creating a binding between main.svelte and Intermediate.svelte (e.g. `bind:object={...}` instead of `object={...}`)'
 	]
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-3/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-3/_config.js
index 66e51843808e..7b8cc676d528 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-3/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-3/_config.js
@@ -33,7 +33,7 @@ export default test({
 		assert.htmlEqual(target.innerHTML, `<button>clicks: 1</button><button>clicks: 1</button>`);
 
 		assert.deepEqual(warnings, [
-			'Counter.svelte mutated a value owned by main.svelte. This is strongly discouraged. Consider passing values to child components with `bind:`, or use a callback instead'
+			'Mutating unbound props (`notshared`, at Counter.svelte:10:23) is strongly discouraged. Consider using `bind:notshared={...}` in main.svelte (or using a callback) instead'
 		]);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-7/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-7/_config.js
index e766a946d0dc..bd2ecc28b6f7 100644
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-7/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-7/_config.js
@@ -1,7 +1,6 @@
 import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
-// Tests that proxies widen ownership correctly even if not directly connected to each other
 export default test({
 	compileOptions: {
 		dev: true
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterBinding.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterBinding.svelte
deleted file mode 100644
index d6da559fb176..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterBinding.svelte
+++ /dev/null
@@ -1,7 +0,0 @@
-<script>
-	let { linked3 = $bindable(), linked4 = $bindable() } = $props();
-</script>
-
-<p>Binding</p>
-<button onclick={() => linked3.count++}>Increment Linked 1 ({linked3.count})</button>
-<button onclick={() => linked4.count++}>Increment Linked 2 ({linked4.count})</button>
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterContext.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterContext.svelte
deleted file mode 100644
index b935f0a472dc..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/CounterContext.svelte
+++ /dev/null
@@ -1,13 +0,0 @@
-<script>
-	import { getContext } from 'svelte';
-	const linked1 = getContext('linked1');
-	const linked2 = getContext('linked2');
-</script>
-
-<p>Context</p>
-<button onclick={() => linked1.linked.current.count++}
-	>Increment Linked 1 ({linked1.linked.current.count})</button
->
-<button onclick={() => linked2.linked.current.count++}
-	>Increment Linked 2 ({linked2.linked.current.count})</button
->
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/_config.js b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/_config.js
deleted file mode 100644
index d6d12d01cd09..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/_config.js
+++ /dev/null
@@ -1,34 +0,0 @@
-import { flushSync } from 'svelte';
-import { test } from '../../test';
-
-// Tests that ownership is widened with $derived (on class or on its own) that contains $state
-export default test({
-	compileOptions: {
-		dev: true
-	},
-
-	test({ assert, target, warnings }) {
-		const [root, counter_context1, counter_context2, counter_binding1, counter_binding2] =
-			target.querySelectorAll('button');
-
-		counter_context1.click();
-		counter_context2.click();
-		counter_binding1.click();
-		counter_binding2.click();
-		flushSync();
-
-		assert.equal(warnings.length, 0);
-
-		root.click();
-		flushSync();
-		counter_context1.click();
-		counter_context2.click();
-		counter_binding1.click();
-		counter_binding2.click();
-		flushSync();
-
-		assert.equal(warnings.length, 0);
-	},
-
-	warnings: []
-});
diff --git a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/main.svelte b/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/main.svelte
deleted file mode 100644
index aaade26e162c..000000000000
--- a/packages/svelte/tests/runtime-runes/samples/non-local-mutation-with-binding-8/main.svelte
+++ /dev/null
@@ -1,46 +0,0 @@
-<script>
-	import CounterBinding from './CounterBinding.svelte';
-	import CounterContext from './CounterContext.svelte';
-	import { setContext } from 'svelte';
-
-	let counter = $state({ count: 0 });
-
-	class Linked {
-		#getter;
-		linked = $derived.by(() => {
-			const state = $state({ current: $state.snapshot(this.#getter()) });
-			return state;
-		});
-
-		constructor(fn) {
-			this.#getter = fn;
-		}
-	}
-
-	const linked1 = $derived.by(() => {
-		const state = $state({ current: $state.snapshot(counter) });
-		return state;
-	});
-	const linked2 = new Linked(() => counter);
-
-	setContext('linked1', {
-		get linked() {
-			return linked1;
-		}
-	});
-	setContext('linked2', linked2);
-
-	const linked3 = $derived.by(() => {
-		const state = $state({ current: $state.snapshot(counter) });
-		return state;
-	});
-	const linked4 = new Linked(() => counter);
-</script>
-
-<p>Parent</p>
-<button onclick={() => counter.count++}>
-	Increment Original ({counter.count})
-</button>
-
-<CounterContext />
-<CounterBinding bind:linked3={linked3.current} bind:linked4={linked4.linked.current} />