diff --git a/packages/perps-controller/CHANGELOG.md b/packages/perps-controller/CHANGELOG.md
index 37f40082a3..78a0855b05 100644
--- a/packages/perps-controller/CHANGELOG.md
+++ b/packages/perps-controller/CHANGELOG.md
@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Handle zero minimum order amounts and margin fractions reported by Lighter for inactive markets by omitting unusable retired rows, while keeping valid delisted metadata and active market values strict. ([#10110](https://github.com/MetaMask/core/pull/10110))
+- Resolve Lighter accounts from sparse address-discovery rows and every API-key slot, settle confirmed missing accounts to an empty state, and preserve the last authoritative state across transport, authentication, and malformed-response failures. ([#10119](https://github.com/MetaMask/core/pull/10119))
+- Accept Lighter trade rows that omit the counterparty's realized PnL while continuing to require a valid PnL for the selected account. ([#10119](https://github.com/MetaMask/core/pull/10119))
+- Stop emitting a debug log for every Lighter price-stream frame. ([#10119](https://github.com/MetaMask/core/pull/10119))
 
 ## [16.1.0]
 
diff --git a/packages/perps-controller/src/providers/LighterProvider.ts b/packages/perps-controller/src/providers/LighterProvider.ts
index f9d1b61ce1..442571d483 100644
--- a/packages/perps-controller/src/providers/LighterProvider.ts
+++ b/packages/perps-controller/src/providers/LighterProvider.ts
@@ -57,6 +57,7 @@ import { PERPS_CONSTANTS } from '../constants/perpsConfig.js';
 import type { PerpsControllerMessenger } from '../PerpsController.js';
 import {
   convertKeysToCamelCase,
+  LighterApiError,
   LighterClientService,
 } from '../services/LighterClientService.js';
 import { LighterWalletService } from '../services/LighterWalletService.js';
@@ -125,6 +126,7 @@ import type {
 import type {
   LighterApiOrder,
   LighterApiPosition,
+  LighterAccountsByL1AddressResponse,
   LighterAuthConfig,
   LighterTxLookupResponse,
   LighterTransferHistoryItem,
@@ -979,6 +981,16 @@ const LIGHTER_SIGNER_UNAVAILABLE_ERROR = 'Lighter signer bridge not configured';
 const LIGHTER_MAINNET_EXPLORER_URL = 'https://scan.lighter.xyz';
 const LIGHTER_TESTNET_EXPLORER_URL = 'https://testnet.zklighter.elliot.ai';
 
+/** A definitive venue response that the selected wallet has no account. */
+class LighterAccountNotFoundError extends Error {
+  constructor(address: string) {
+    super(
+      `No Lighter account exists for ${address}; fund it via the bridge (or the testnet faucet) first`,
+    );
+    this.name = 'LighterAccountNotFoundError';
+  }
+}
+
 /**
  * Empty account state returned when reads fail or no account exists.
  */
@@ -1048,9 +1060,6 @@ export class LighterProvider implements PerpsProvider {
 
   #priceWs: LighterWebSocketLike | null = null;
 
-  /** Monotonic poll counter — surfaced in debug logs so e2e can assert liveness. */
-  #pricePollCycle = 0;
-
   /** Injectable WebSocket constructor (null → REST polling fallback). */
   readonly #webSocketCtor: LighterWebSocketCtor | null;
 
@@ -1570,7 +1579,15 @@ export class LighterProvider implements PerpsProvider {
     }
     const generation = this.#sessionGeneration;
     const address = this.#walletService.getUserAddress();
-    const response = await this.#clientService.getAccountsByL1Address(address);
+    let response: LighterAccountsByL1AddressResponse;
+    try {
+      response = await this.#clientService.getAccountsByL1Address(address);
+    } catch (error) {
+      if (error instanceof LighterApiError && error.code === 21100) {
+        throw new LighterAccountNotFoundError(address);
+      }
+      throw error;
+    }
     // Re-run the binding so an EXTERNAL switch nothing else observed also
     // advances the generation, then compare: caching after any switch
     // would poison the new session with the old account. Retry instead.
@@ -1579,9 +1596,7 @@ export class LighterProvider implements PerpsProvider {
       return await this.#ensureAccountIndex();
     }
     if (!response.subAccounts?.length) {
-      throw new Error(
-        `No Lighter account exists for ${address}; fund it via the bridge (or the testnet faucet) first`,
-      );
+      throw new LighterAccountNotFoundError(address);
     }
     const master = response.subAccounts.reduce((min, account) =>
       account.index < min.index ? account : min,
@@ -4250,10 +4265,11 @@ export class LighterProvider implements PerpsProvider {
   readonly #isVenueKeyRegistered = async (
     accountIndex: number,
   ): Promise<boolean> => {
-    const response = await this.#clientService.getApiKeys(
-      accountIndex,
-      this.#apiKeyIndex,
-    );
+    // Query all slots. Lighter returns `api key not found` when a missing
+    // slot is requested directly, which would make first-time registration
+    // impossible. The all-slots response is successful and represents an
+    // unused slot by omitting it from `apiKeys`.
+    const response = await this.#clientService.getApiKeys(accountIndex);
     const configuredSlot = response.apiKeys.find(
       (key) => key.apiKeyIndex === this.#apiKeyIndex,
     );
@@ -7610,8 +7626,8 @@ export class LighterProvider implements PerpsProvider {
 
   /**
    * Resolve the Lighter account index and request the account-scoped
-   * channels. Without a Lighter account, account-scoped subscribers receive
-   * one empty emission unless the failure is a capability refusal.
+   * channels. When the venue definitively reports no Lighter account,
+   * account-scoped subscribers receive an empty emission.
    */
   readonly #ensureAccountChannels = (): void => {
     if (this.#isDisconnected) {
@@ -7657,11 +7673,23 @@ export class LighterProvider implements PerpsProvider {
           '[LighterProvider] account channels unavailable',
           { error: String(error) },
         );
+        // A venue-confirmed absent account is authoritative empty state for
+        // this exact wallet binding. It must settle initial subscribers so
+        // clients do not render loading skeletons forever. All other failures
+        // preserve the last snapshot: transport, malformed data, auth and
+        // capability errors cannot prove that the account is empty.
+        this.#ensureSessionBinding();
+        if (
+          error instanceof LighterAccountNotFoundError &&
+          generation === this.#sessionGeneration
+        ) {
+          this.#emitAccountBindingReset();
+        }
         // An aborted previous-account setup has no authority over the new
         // session. Current-session failures also preserve the last known data.
-        // Discovery, transport, auth, capability, and integrity failures are
-        // not authoritative empty account state. Explicit account switches
-        // and deselection already emit their synchronous reset.
+        // Transport, auth, capability, and integrity failures are not
+        // authoritative empty account state. Explicit account switches and
+        // deselection already emit their synchronous reset.
       }
     })();
     this.#accountChannelsPromise = setupPromise;
@@ -7883,7 +7911,7 @@ export class LighterProvider implements PerpsProvider {
       const updates = Object.values(message.marketStats).map((stat) =>
         adaptPriceUpdateFromLighterWsStat(stat, timestamp),
       );
-      this.#dispatchPriceUpdates(updates, 'ws');
+      this.#dispatchPriceUpdates(updates);
       this.#dispatchOICaps(Object.values(message.marketStats));
       return;
     }
@@ -8268,29 +8296,21 @@ export class LighterProvider implements PerpsProvider {
     const updates = (response.orderBookDetails ?? []).map((detail) =>
       adaptPriceUpdateFromLighter(detail, timestamp),
     );
-    this.#dispatchPriceUpdates(updates, 'poll');
+    this.#dispatchPriceUpdates(updates);
   };
 
   /**
    * Fan price updates out to every subscriber, honoring symbol filters.
    *
    * @param updates - Adapted price updates for this cycle.
-   * @param transport - Which transport produced the cycle (ws or poll).
    */
-  readonly #dispatchPriceUpdates = (
-    updates: PriceUpdate[],
-    transport: string,
-  ): void => {
+  readonly #dispatchPriceUpdates = (updates: PriceUpdate[]): void => {
     if (this.#isDisconnected || updates.length === 0) {
       return;
     }
     for (const update of updates) {
       this.#lastPriceBySymbol.set(update.symbol, update);
     }
-    this.#pricePollCycle += 1;
-    this.#deps.debugLogger.log(
-      `[LighterProvider] price stream cycle=${this.#pricePollCycle} transport=${transport} updates=${updates.length}`,
-    );
     for (const subscriber of this.#priceSubscribers) {
       this.#deliverPrices(subscriber, updates);
     }
diff --git a/packages/perps-controller/src/services/LighterClientService.ts b/packages/perps-controller/src/services/LighterClientService.ts
index 3f0dc14645..7909516420 100644
--- a/packages/perps-controller/src/services/LighterClientService.ts
+++ b/packages/perps-controller/src/services/LighterClientService.ts
@@ -157,6 +157,15 @@ const AccountStruct = type({
   availableBalance: NonNegativeDecimalStringStruct,
   positions: optional(array(PositionStruct)),
 });
+// The address-discovery endpoint is an identity lookup, not a financial read:
+// live responses can carry sparse balance fields (for example an empty
+// `availableBalance`). Validate only the fields its sole consumer needs. Full
+// account reads retain AccountStruct and its strict financial validation.
+const AccountSummaryStruct = type({
+  accountType: SafeIntegerStruct,
+  index: NonNegativeIntegerStruct,
+  l1Address: string(),
+});
 const MarketBaseStruct = type({
   symbol: string(),
   marketId: NonNegativeIntegerStruct,
@@ -259,8 +268,8 @@ const TradeStruct = type({
   bidAccountId: NonNegativeIntegerStruct,
   isMakerAsk: boolean(),
   timestamp: NonNegativeIntegerStruct,
-  askAccountPnl: SignedDecimalStringStruct,
-  bidAccountPnl: SignedDecimalStringStruct,
+  askAccountPnl: optional(SignedDecimalStringStruct),
+  bidAccountPnl: optional(SignedDecimalStringStruct),
   takerFee: optional(NonNegativeFinancialNumberStruct),
   makerFee: optional(NonNegativeFinancialNumberStruct),
   takerPositionSizeBefore: NonNegativeDecimalStringStruct,
@@ -285,7 +294,7 @@ const ResponseStructs = {
   accountsByAddress: type({
     ...BaseResponseStruct.schema,
     l1Address: string(),
-    subAccounts: array(AccountStruct),
+    subAccounts: array(AccountSummaryStruct),
   }),
   apiKeys: type({
     ...BaseResponseStruct.schema,
diff --git a/packages/perps-controller/src/types/lighter-types.ts b/packages/perps-controller/src/types/lighter-types.ts
index 94e6b528c1..0f3e19345c 100644
--- a/packages/perps-controller/src/types/lighter-types.ts
+++ b/packages/perps-controller/src/types/lighter-types.ts
@@ -401,6 +401,19 @@ export type LighterSubAccount = {
   positions?: LighterApiPosition[];
 };
 
+/**
+ * Identity fields returned by `GET /api/v1/accountsByL1Address`.
+ *
+ * Lighter's address-discovery endpoint may leave balance fields empty even
+ * though the full `account` endpoint returns validated decimal values. Account
+ * discovery only consumes these identity fields; financial reads continue to
+ * use {@link LighterSubAccount} and its stricter response validation.
+ */
+export type LighterAccountSummary = Pick<
+  LighterSubAccount,
+  'accountType' | 'index' | 'l1Address'
+>;
+
 /**
  * Response of `GET /api/v1/accountsByL1Address`.
  */
@@ -408,7 +421,7 @@ export type LighterAccountsByL1AddressResponse = {
   code: number;
   message?: string;
   l1Address: string;
-  subAccounts: LighterSubAccount[];
+  subAccounts: LighterAccountSummary[];
 };
 
 /**
@@ -657,9 +670,9 @@ export type LighterRestTrade = {
   isMakerAsk: boolean;
   timestamp: number;
   /** Realized pnl for the ask-side account, signed USDC. */
-  askAccountPnl: string;
+  askAccountPnl?: string;
   /** Realized pnl for the bid-side account, signed USDC. */
-  bidAccountPnl: string;
+  bidAccountPnl?: string;
   /**
    * Taker/maker fees, present when nonzero. The official model types them
    * as StrictInt with NO documented unit or scale; until a captured
diff --git a/packages/perps-controller/tests/src/providers/LighterProvider.test.ts b/packages/perps-controller/tests/src/providers/LighterProvider.test.ts
index 6a5a597362..3203661eb6 100644
--- a/packages/perps-controller/tests/src/providers/LighterProvider.test.ts
+++ b/packages/perps-controller/tests/src/providers/LighterProvider.test.ts
@@ -942,10 +942,13 @@ describe('LighterProvider', () => {
       expect(result.error).toContain('signer bridge');
     });
 
-    it('sets up the signer and registers the venue key when missing', async () => {
+    it('queries all API-key slots and registers the venue key when the configured slot is missing', async () => {
       const { provider, clientInstance, calls, bridge } = buildProvider();
       const result = await provider.isReadyToTrade();
       expect(result.ready).toBe(true);
+      // A direct lookup of an unused slot returns venue error 21109
+      // (`api key not found`); querying all slots returns an empty list.
+      expect(clientInstance.getApiKeys).toHaveBeenCalledWith(28);
       expect(bridge.createClient).toHaveBeenCalledWith({
         chainId: 300,
         accountIndex: 28,
@@ -1837,6 +1840,35 @@ describe('LighterProvider', () => {
       await provider.disconnect();
     });
 
+    it('does not log every price-stream frame', async () => {
+      const infra = createMockInfrastructure();
+      const { provider } = buildProvider({
+        webSocketCtor: fakeCtor,
+        platformDependencies: infra,
+      });
+      const unsubscribe = provider.subscribeToPrices({
+        symbols: [],
+        callback: jest.fn(),
+      });
+      const socket = FakeWebSocket.instances[0];
+      socket.open();
+
+      socket.receive({
+        type: 'subscribed/market_stats',
+        market_stats: { '1': wsStat('BTC', 1, '63000.5') },
+      });
+      socket.receive({
+        type: 'update/market_stats',
+        market_stats: { '1': wsStat('BTC', 1, '63001.5') },
+      });
+
+      expect(infra.debugLogger.log).not.toHaveBeenCalledWith(
+        expect.stringContaining('[LighterProvider] price stream cycle='),
+      );
+      unsubscribe();
+      await provider.disconnect();
+    });
+
     it('replays the merged snapshot to late subscribers with symbol filters', async () => {
       const { provider } = buildProvider({ webSocketCtor: fakeCtor });
       const unsubscribeFirst = provider.subscribeToPrices({
@@ -2185,6 +2217,74 @@ describe('LighterProvider', () => {
       await provider.disconnect();
     });
 
+    it('emits authoritative empty state when the selected wallet has no Lighter account', async () => {
+      const { provider, clientInstance } = buildProvider({
+        webSocketCtor: fakeCtor,
+        configuredAccountIndex: null,
+      });
+      clientInstance.getAccountsByL1Address.mockRejectedValue(
+        new LighterApiError('account not found', 21100),
+      );
+      const accountCallback = jest.fn();
+      const positionsCallback = jest.fn();
+      const ordersCallback = jest.fn();
+      const unsubscribeAccount = provider.subscribeToAccount({
+        callback: accountCallback,
+      });
+      const unsubscribePositions = provider.subscribeToPositions({
+        callback: positionsCallback,
+      });
+      const unsubscribeOrders = provider.subscribeToOrders({
+        callback: ordersCallback,
+      });
+
+      await new Promise((resolveTick) => setImmediate(resolveTick));
+      await new Promise((resolveTick) => setImmediate(resolveTick));
+
+      expect(accountCallback).toHaveBeenCalledWith(
+        expect.objectContaining({
+          totalBalance: '0',
+          spendableBalance: '0',
+          providerId: 'lighter',
+        }),
+      );
+      expect(positionsCallback).toHaveBeenCalledWith([]);
+      expect(ordersCallback).toHaveBeenCalledWith([]);
+      unsubscribeAccount();
+      unsubscribePositions();
+      unsubscribeOrders();
+      await provider.disconnect();
+    });
+
+    it('also settles account subscribers when discovery succeeds with no accounts', async () => {
+      const { provider, clientInstance } = buildProvider({
+        webSocketCtor: fakeCtor,
+        configuredAccountIndex: null,
+      });
+      clientInstance.getAccountsByL1Address.mockResolvedValue({
+        code: 200,
+        l1Address: ACCOUNT.l1Address,
+        subAccounts: [],
+      });
+      const positionsCallback = jest.fn();
+      const ordersCallback = jest.fn();
+      const unsubscribePositions = provider.subscribeToPositions({
+        callback: positionsCallback,
+      });
+      const unsubscribeOrders = provider.subscribeToOrders({
+        callback: ordersCallback,
+      });
+
+      await new Promise((resolveTick) => setImmediate(resolveTick));
+      await new Promise((resolveTick) => setImmediate(resolveTick));
+
+      expect(positionsCallback).toHaveBeenCalledWith([]);
+      expect(ordersCallback).toHaveBeenCalledWith([]);
+      unsubscribePositions();
+      unsubscribeOrders();
+      await provider.disconnect();
+    });
+
     it('does not clear orders when authenticated channel setup fails', async () => {
       const { provider, bridge } = buildProvider({
         webSocketCtor: fakeCtor,
diff --git a/packages/perps-controller/tests/src/services/LighterClientService.test.ts b/packages/perps-controller/tests/src/services/LighterClientService.test.ts
index e361c3741e..4ea23fd52b 100644
--- a/packages/perps-controller/tests/src/services/LighterClientService.test.ts
+++ b/packages/perps-controller/tests/src/services/LighterClientService.test.ts
@@ -342,7 +342,6 @@ describe('LighterClientService', () => {
       ['negative size', { size: '-0.1' }],
       ['zero price', { price: '0' }],
       ['negative position magnitude', { taker_position_size_before: '-0.1' }],
-      ['missing account pnl', { ask_account_pnl: undefined }],
       ['missing maker role', { is_maker_ask: undefined }],
       [
         'missing position sign context',
@@ -360,6 +359,28 @@ describe('LighterClientService', () => {
         buildService().getTrades(28, 'auth-token', { limit: 50 }),
       ).rejects.toThrow('Invalid Lighter venue data');
     });
+
+    it('accepts omitted account pnl fields for later participant-side validation', async () => {
+      const {
+        ask_account_pnl: _askPnl,
+        bid_account_pnl: _bidPnl,
+        ...trade
+      } = VALID_TRADE_WIRE;
+      fetchMock.mockResolvedValue(
+        mockJsonResponse({
+          code: 200,
+          trades: [trade],
+        }),
+      );
+
+      const response = await buildService().getTrades(28, 'auth-token', {
+        limit: 50,
+      });
+
+      expect(response.trades).toHaveLength(1);
+      expect(response.trades[0]).not.toHaveProperty('askAccountPnl');
+      expect(response.trades[0]).not.toHaveProperty('bidAccountPnl');
+    });
   });
 
   describe('financial history decoders', () => {
@@ -576,6 +597,49 @@ describe('LighterClientService', () => {
       );
     });
 
+    it('accepts sparse account-discovery balances without weakening full account reads', async () => {
+      const discoveryAccount = {
+        code: 0,
+        account_type: 0,
+        index: 629696,
+        l1_address: '0xabc',
+        cancel_all_time: 0,
+        total_order_count: 0,
+        pending_order_count: 0,
+        status: 0,
+        collateral: '5.000000',
+        available_balance: '',
+      };
+      fetchMock.mockResolvedValueOnce(
+        mockJsonResponse({
+          code: 200,
+          l1_address: '0xabc',
+          sub_accounts: [discoveryAccount],
+        }),
+      );
+      const service = buildService(false);
+
+      const discovered = await service.getAccountsByL1Address('0xabc');
+      expect(discovered).toStrictEqual(
+        expect.objectContaining({
+          subAccounts: [
+            expect.objectContaining({
+              accountType: 0,
+              index: 629696,
+              l1Address: '0xabc',
+            }),
+          ],
+        }),
+      );
+
+      fetchMock.mockResolvedValueOnce(
+        mockJsonResponse({ code: 200, accounts: [discoveryAccount] }),
+      );
+      await expect(service.getAccountByIndex(629696)).rejects.toThrow(
+        'Invalid Lighter venue data',
+      );
+    });
+
     it('queries the account by index', async () => {
       fetchMock.mockResolvedValue(
         mockJsonResponse({ code: 200, accounts: [] }),
diff --git a/packages/perps-controller/tests/src/utils/lighterAdapter.test.ts b/packages/perps-controller/tests/src/utils/lighterAdapter.test.ts
index 3b00f4fd30..34d699d534 100644
--- a/packages/perps-controller/tests/src/utils/lighterAdapter.test.ts
+++ b/packages/perps-controller/tests/src/utils/lighterAdapter.test.ts
@@ -534,6 +534,23 @@ describe('lighterAdapter', () => {
       ).toThrow('Invalid Lighter venue data');
     });
 
+    it('accepts omitted counterparty pnl while requiring the selected account pnl', () => {
+      expect(
+        adaptFillFromLighterTrade(
+          { ...REAL_TRADE, bidAccountPnl: undefined },
+          'SOL',
+          28,
+        ).pnl,
+      ).toBe('-0.012901');
+      expect(
+        adaptFillFromLighterTrade(
+          { ...REAL_TRADE, askAccountPnl: undefined },
+          'SOL',
+          7,
+        ).pnl,
+      ).toBe('0');
+    });
+
     it('keeps a Standard fill whose Premium counterparty paid the fee', () => {
       // Account 28 is the taker; the MAKER (counterparty) fee being nonzero
       // must not drop our valid zero-fee fill.