diff --git a/apps/api/src/app/portfolio/portfolio.service.spec.ts b/apps/api/src/app/portfolio/portfolio.service.spec.ts
new file mode 100644
index 000000000..da846c45d
--- /dev/null
+++ b/apps/api/src/app/portfolio/portfolio.service.spec.ts
@@ -0,0 +1,272 @@
+import { AccountService } from '@ghostfolio/api/app/account/account.service';
+import { CashDetails } from '@ghostfolio/api/app/account/interfaces/cash-details.interface';
+import { ActivitiesService } from '@ghostfolio/api/app/activities/activities.service';
+import { userDummyData } from '@ghostfolio/api/app/portfolio/calculator/portfolio-calculator-test-utils';
+import { PortfolioCalculatorFactory } from '@ghostfolio/api/app/portfolio/calculator/portfolio-calculator.factory';
+import { UserService } from '@ghostfolio/api/app/user/user.service';
+import { ConfigurationService } from '@ghostfolio/api/services/configuration/configuration.service';
+import { DataProviderService } from '@ghostfolio/api/services/data-provider/data-provider.service';
+import { ExchangeRateDataService } from '@ghostfolio/api/services/exchange-rate-data/exchange-rate-data.service';
+import { ImpersonationService } from '@ghostfolio/api/services/impersonation/impersonation.service';
+import { SymbolProfileService } from '@ghostfolio/api/services/symbol-profile/symbol-profile.service';
+import { parseDate } from '@ghostfolio/common/helper';
+
+import { Account, DataSource } from '@prisma/client';
+import { Big } from 'big.js';
+import { randomUUID } from 'node:crypto';
+
+import { PortfolioService } from './portfolio.service';
+
+describe('PortfolioService', () => {
+  let accountService: AccountService;
+  let activitiesService: ActivitiesService;
+  let configurationService: ConfigurationService;
+  let dataProviderService: DataProviderService;
+  let exchangeRateDataService: ExchangeRateDataService;
+  let impersonationService: ImpersonationService;
+  let portfolioCalculatorFactory: PortfolioCalculatorFactory;
+  let portfolioService: PortfolioService;
+  let symbolProfileService: SymbolProfileService;
+  let userService: UserService;
+
+  beforeEach(() => {
+    configurationService = new ConfigurationService();
+
+    dataProviderService = new DataProviderService(
+      configurationService,
+      null,
+      null,
+      null,
+      null,
+      null
+    );
+
+    exchangeRateDataService = new ExchangeRateDataService(
+      null,
+      null,
+      null,
+      null
+    );
+
+    accountService = new AccountService(
+      null,
+      null,
+      exchangeRateDataService,
+      null
+    );
+
+    activitiesService = new ActivitiesService(
+      null,
+      accountService,
+      null,
+      dataProviderService,
+      null,
+      exchangeRateDataService,
+      null,
+      null
+    );
+
+    impersonationService = new ImpersonationService(null, null);
+
+    portfolioCalculatorFactory = new PortfolioCalculatorFactory(
+      configurationService,
+      null,
+      exchangeRateDataService,
+      null,
+      null
+    );
+
+    symbolProfileService = new SymbolProfileService(null);
+
+    userService = new UserService(
+      null,
+      null,
+      null,
+      null,
+      null,
+      null,
+      null,
+      null
+    );
+
+    portfolioService = new PortfolioService(
+      null,
+      accountService,
+      activitiesService,
+      null,
+      portfolioCalculatorFactory,
+      dataProviderService,
+      exchangeRateDataService,
+      null,
+      impersonationService,
+      null,
+      null,
+      symbolProfileService,
+      userService
+    );
+  });
+
+  describe('getCashSymbolProfiles', () => {
+    it('should use the exchange-rate data source so the symbol-profile join in getDetails matches the calculator positions', () => {
+      jest
+        .spyOn(dataProviderService, 'getDataSourceForExchangeRates')
+        .mockReturnValue(DataSource.YAHOO);
+
+      const cashDetails: CashDetails = {
+        accounts: [
+          {
+            balance: 2000,
+            comment: null,
+            createdAt: parseDate('2024-01-01'),
+            currency: 'USD',
+            id: randomUUID(),
+            isExcluded: false,
+            name: 'USD',
+            platformId: null,
+            updatedAt: parseDate('2024-01-01'),
+            userId: userDummyData.id
+          }
+        ],
+        balanceInBaseCurrency: 1820
+      };
+
+      const assetProfiles = (
+        portfolioService as unknown as {
+          getCashSymbolProfiles: (
+            aCashDetails: CashDetails
+          ) => { dataSource: DataSource; symbol: string }[];
+        }
+      ).getCashSymbolProfiles(cashDetails);
+
+      expect(assetProfiles).toHaveLength(1);
+      expect(assetProfiles[0].dataSource).toBe(DataSource.YAHOO);
+      expect(assetProfiles[0].symbol).toBe('USD');
+    });
+  });
+
+  describe('getDetails', () => {
+    it('should return cash holdings when the calculator emits cash positions with the exchange-rate data source', async () => {
+      const accountId = randomUUID();
+
+      const cashAccount: Account = {
+        balance: 2000,
+        comment: null,
+        createdAt: parseDate('2024-01-01'),
+        currency: 'USD',
+        id: accountId,
+        isExcluded: false,
+        name: 'USD',
+        platformId: null,
+        updatedAt: parseDate('2024-01-01'),
+        userId: userDummyData.id
+      };
+
+      jest.spyOn(accountService, 'getCashDetails').mockResolvedValue({
+        accounts: [cashAccount],
+        balanceInBaseCurrency: 1820
+      });
+
+      jest
+        .spyOn(activitiesService, 'getActivitiesForPortfolioCalculator')
+        .mockResolvedValue({ activities: [], count: 0 });
+
+      jest
+        .spyOn(dataProviderService, 'getDataSourceForExchangeRates')
+        .mockReturnValue(DataSource.YAHOO);
+
+      jest
+        .spyOn(impersonationService, 'validateImpersonationId')
+        .mockResolvedValue(null);
+
+      jest
+        .spyOn(symbolProfileService, 'getSymbolProfiles')
+        .mockResolvedValue([]);
+
+      jest.spyOn(userService, 'user').mockResolvedValue({
+        accessesGet: [],
+        accounts: [],
+        activityCount: 0,
+        dataProviderGhostfolioDailyRequests: 0,
+        id: userDummyData.id,
+        settings: {
+          settings: {
+            baseCurrency: 'CHF'
+          }
+        }
+      } as unknown as Awaited<ReturnType<typeof userService.user>>);
+
+      const usdPosition = {
+        activitiesCount: 1,
+        averagePrice: new Big(1),
+        currency: 'USD',
+        dataSource: DataSource.YAHOO,
+        dateOfFirstActivity: '2024-01-01',
+        dividend: new Big(0),
+        dividendInBaseCurrency: new Big(0),
+        fee: new Big(0),
+        feeInBaseCurrency: new Big(0),
+        grossPerformance: new Big(0),
+        grossPerformancePercentage: new Big(0),
+        grossPerformancePercentageWithCurrencyEffect: new Big(0),
+        grossPerformanceWithCurrencyEffect: new Big(0),
+        investment: new Big(1820),
+        investmentWithCurrencyEffect: new Big(1820),
+        marketPrice: 1,
+        marketPriceInBaseCurrency: 0.91,
+        netPerformance: new Big(0),
+        netPerformancePercentage: new Big(0),
+        netPerformancePercentageWithCurrencyEffectMap: {},
+        netPerformanceWithCurrencyEffectMap: {},
+        quantity: new Big(2000),
+        symbol: 'USD',
+        tags: [],
+        timeWeightedInvestment: new Big(0),
+        timeWeightedInvestmentWithCurrencyEffect: new Big(0),
+        valueInBaseCurrency: new Big(1820)
+      };
+
+      jest
+        .spyOn(portfolioCalculatorFactory, 'createCalculator')
+        .mockReturnValue({
+          getSnapshot: jest.fn().mockResolvedValue({
+            activitiesCount: 1,
+            createdAt: parseDate('2024-01-01'),
+            currentValueInBaseCurrency: new Big(1820),
+            errors: [],
+            hasErrors: false,
+            historicalData: [],
+            positions: [usdPosition],
+            totalFeesWithCurrencyEffect: new Big(0),
+            totalInterestWithCurrencyEffect: new Big(0),
+            totalInvestment: new Big(1820),
+            totalInvestmentWithCurrencyEffect: new Big(1820),
+            totalLiabilitiesWithCurrencyEffect: new Big(0)
+          })
+        } as unknown as ReturnType<
+          typeof portfolioCalculatorFactory.createCalculator
+        >);
+
+      jest
+        .spyOn(
+          portfolioService as unknown as {
+            getValueOfAccountsAndPlatforms: () => Promise<{
+              accounts: object;
+              platforms: object;
+            }>;
+          },
+          'getValueOfAccountsAndPlatforms'
+        )
+        .mockResolvedValue({ accounts: {}, platforms: {} });
+
+      const { holdings } = await portfolioService.getDetails({
+        filters: [],
+        impersonationId: userDummyData.id,
+        userId: userDummyData.id
+      });
+
+      expect(holdings['USD']).toBeDefined();
+      expect(holdings['USD'].assetProfile.dataSource).toBe(DataSource.YAHOO);
+      expect(holdings['USD'].assetProfile.symbol).toBe('USD');
+    });
+  });
+});