Bugfix/investment calculation when selling all units of holding (#5509)

* Fix investment calculation when selling all units of holding

* Update changelog

---------

Co-authored-by: Thomas Kaul <4159106+dtslvr@users.noreply.github.com>

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Fixed an issue where the save button was not enabled after editing tags in the create or update activity dialog
+- Fixed an issue in the investment calculation when selling all units of a holding
 
 ## 2.201.0 - 2025-09-24
 

apps/api/src/app/portfolio/calculator/portfolio-calculator.ts

@@ -922,7 +922,7 @@ export abstract class PortfolioCalculator {
       if (oldAccumulatedSymbol) {
         let investment = oldAccumulatedSymbol.investment;
 
-        const newQuantity = quantity
+        let newQuantity = quantity
           .mul(factor)
           .plus(oldAccumulatedSymbol.quantity);
 
@@ -948,6 +948,12 @@ export abstract class PortfolioCalculator {
           }
         }
 
+        if (newQuantity.abs().lt(Number.EPSILON)) {
+          // Reset to zero if quantity is (almost) zero to avoid rounding issues
+          investment = new Big(0);
+          newQuantity = new Big(0);
+        }
+
         currentTransactionPointItem = {
           currency,
           dataSource,

apps/api/src/app/portfolio/calculator/roai/portfolio-calculator-msft-buy-and-sell.spec.ts

@@ -0,0 +1,146 @@
+import { Activity } from '@ghostfolio/api/app/order/interfaces/activities.interface';
+import {
+  activityDummyData,
+  symbolProfileDummyData,
+  userDummyData
+} from '@ghostfolio/api/app/portfolio/calculator/portfolio-calculator-test-utils';
+import { PortfolioCalculatorFactory } from '@ghostfolio/api/app/portfolio/calculator/portfolio-calculator.factory';
+import { CurrentRateService } from '@ghostfolio/api/app/portfolio/current-rate.service';
+import { CurrentRateServiceMock } from '@ghostfolio/api/app/portfolio/current-rate.service.mock';
+import { RedisCacheService } from '@ghostfolio/api/app/redis-cache/redis-cache.service';
+import { RedisCacheServiceMock } from '@ghostfolio/api/app/redis-cache/redis-cache.service.mock';
+import { ConfigurationService } from '@ghostfolio/api/services/configuration/configuration.service';
+import { ExchangeRateDataService } from '@ghostfolio/api/services/exchange-rate-data/exchange-rate-data.service';
+import { PortfolioSnapshotService } from '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.service';
+import { PortfolioSnapshotServiceMock } from '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.service.mock';
+import { parseDate } from '@ghostfolio/common/helper';
+import { PerformanceCalculationType } from '@ghostfolio/common/types/performance-calculation-type.type';
+
+jest.mock('@ghostfolio/api/app/portfolio/current-rate.service', () => {
+  return {
+    CurrentRateService: jest.fn().mockImplementation(() => {
+      return CurrentRateServiceMock;
+    })
+  };
+});
+
+jest.mock(
+  '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.service',
+  () => {
+    return {
+      // eslint-disable-next-line @typescript-eslint/naming-convention
+      PortfolioSnapshotService: jest.fn().mockImplementation(() => {
+        return PortfolioSnapshotServiceMock;
+      })
+    };
+  }
+);
+
+jest.mock('@ghostfolio/api/app/redis-cache/redis-cache.service', () => {
+  return {
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    RedisCacheService: jest.fn().mockImplementation(() => {
+      return RedisCacheServiceMock;
+    })
+  };
+});
+
+describe('PortfolioCalculator', () => {
+  let configurationService: ConfigurationService;
+  let currentRateService: CurrentRateService;
+  let exchangeRateDataService: ExchangeRateDataService;
+  let portfolioCalculatorFactory: PortfolioCalculatorFactory;
+  let portfolioSnapshotService: PortfolioSnapshotService;
+  let redisCacheService: RedisCacheService;
+
+  beforeEach(() => {
+    configurationService = new ConfigurationService();
+    currentRateService = new CurrentRateService(null, null, null, null);
+    exchangeRateDataService = new ExchangeRateDataService(
+      null,
+      null,
+      null,
+      null
+    );
+    portfolioSnapshotService = new PortfolioSnapshotService(null);
+    redisCacheService = new RedisCacheService(null, null);
+    portfolioCalculatorFactory = new PortfolioCalculatorFactory(
+      configurationService,
+      currentRateService,
+      exchangeRateDataService,
+      portfolioSnapshotService,
+      redisCacheService
+    );
+  });
+
+  describe('get transaction point', () => {
+    it('with MSFT buy and sell with fractional quantities (multiples of 1/3)', () => {
+      jest.useFakeTimers().setSystemTime(parseDate('2024-04-01').getTime());
+
+      const activities: Activity[] = [
+        {
+          ...activityDummyData,
+          date: new Date('2024-03-08'),
+          feeInAssetProfileCurrency: 0,
+          quantity: 0.3333333333333333,
+          SymbolProfile: {
+            ...symbolProfileDummyData,
+            currency: 'USD',
+            dataSource: 'YAHOO',
+            name: 'Microsoft Inc.',
+            symbol: 'MSFT'
+          },
+          type: 'BUY',
+          unitPriceInAssetProfileCurrency: 408
+        },
+        {
+          ...activityDummyData,
+          date: new Date('2024-03-13'),
+          quantity: 0.6666666666666666,
+          feeInAssetProfileCurrency: 0,
+          SymbolProfile: {
+            ...symbolProfileDummyData,
+            currency: 'USD',
+            dataSource: 'YAHOO',
+            name: 'Microsoft Inc.',
+            symbol: 'MSFT'
+          },
+          type: 'BUY',
+          unitPriceInAssetProfileCurrency: 400
+        },
+        {
+          ...activityDummyData,
+          date: new Date('2024-03-14'),
+          quantity: 1,
+          feeInAssetProfileCurrency: 0,
+          SymbolProfile: {
+            ...symbolProfileDummyData,
+            currency: 'USD',
+            dataSource: 'YAHOO',
+            name: 'Microsoft Inc.',
+            symbol: 'MSFT'
+          },
+          type: 'SELL',
+          unitPriceInAssetProfileCurrency: 411
+        }
+      ];
+
+      const portfolioCalculator = portfolioCalculatorFactory.createCalculator({
+        activities,
+        calculationType: PerformanceCalculationType.ROAI,
+        currency: 'USD',
+        userId: userDummyData.id
+      });
+
+      const transactionPoints = portfolioCalculator.getTransactionPoints();
+      const lastTransactionPoint =
+        transactionPoints[transactionPoints.length - 1];
+      const position = lastTransactionPoint.items.find(
+        (item) => item.symbol === 'MSFT'
+      );
+
+      expect(position.investment.toNumber()).toBe(0);
+      expect(position.quantity.toNumber()).toBe(0);
+    });
+  });
+});