diff --git a/CHANGELOG.md b/CHANGELOG.md
index b5d72f98..d0b69880 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Improved the export functionality by applying filters on accounts and tags
 - Improved the symbol validation in the _Yahoo Finance_ service (get asset profiles)
+- Eliminated `firstOrderDate` from the summary of the portfolio details endpoint in favor of using `dateOfFirstActivity` from the user endpoint
 - Refactored `lodash.uniq` with `Array.from(new Set(...))`
 - Refreshed the cryptocurrencies list
 - Improved the language localization for Turkish (`tr`)
diff --git a/apps/api/src/app/portfolio/portfolio.service.ts b/apps/api/src/app/portfolio/portfolio.service.ts
index a3d9e3c4..c7eff27d 100644
--- a/apps/api/src/app/portfolio/portfolio.service.ts
+++ b/apps/api/src/app/portfolio/portfolio.service.ts
@@ -1918,7 +1918,6 @@ export class PortfolioService {
       annualizedPerformancePercentWithCurrencyEffect,
       cash,
       excludedAccountsAndActivities,
-      firstOrderDate,
       netPerformance,
       netPerformancePercentage,
       netPerformancePercentageWithCurrencyEffect,
diff --git a/apps/api/src/helper/object.helper.spec.ts b/apps/api/src/helper/object.helper.spec.ts
index 85fb8f4e..b0370fa3 100644
--- a/apps/api/src/helper/object.helper.spec.ts
+++ b/apps/api/src/helper/object.helper.spec.ts
@@ -1519,7 +1519,6 @@ describe('redactAttributes', () => {
             annualizedPerformancePercentWithCurrencyEffect: 0.1694019484552876,
             cash: null,
             excludedAccountsAndActivities: null,
-            firstOrderDate: '2017-01-02T23:00:00.000Z',
             netPerformance: null,
             netPerformancePercentage: 2.3039314216696174,
             netPerformancePercentageWithCurrencyEffect: 2.3589806001456606,
@@ -3023,7 +3022,6 @@ describe('redactAttributes', () => {
         annualizedPerformancePercentWithCurrencyEffect: 0.1694019484552876,
         cash: null,
         excludedAccountsAndActivities: null,
-        firstOrderDate: '2017-01-02T23:00:00.000Z',
         netPerformance: null,
         netPerformancePercentage: 2.3039314216696174,
         netPerformancePercentageWithCurrencyEffect: 2.3589806001456606,
diff --git a/apps/client/src/app/components/portfolio-summary/portfolio-summary.component.ts b/apps/client/src/app/components/portfolio-summary/portfolio-summary.component.ts
index 25f7d930..a44eacc9 100644
--- a/apps/client/src/app/components/portfolio-summary/portfolio-summary.component.ts
+++ b/apps/client/src/app/components/portfolio-summary/portfolio-summary.component.ts
@@ -40,8 +40,8 @@ export class PortfolioSummaryComponent implements OnChanges {
 
   public ngOnChanges() {
     if (this.summary) {
-      if (this.summary.firstOrderDate) {
-        this.timeInMarket = formatDistanceToNow(this.summary.firstOrderDate, {
+      if (this.user.dateOfFirstActivity) {
+        this.timeInMarket = formatDistanceToNow(this.user.dateOfFirstActivity, {
           locale: getDateFnsLocale(this.language)
         });
       } else {
diff --git a/apps/client/src/app/services/data.service.ts b/apps/client/src/app/services/data.service.ts
index 4eba3fff..5ee49d63 100644
--- a/apps/client/src/app/services/data.service.ts
+++ b/apps/client/src/app/services/data.service.ts
@@ -529,12 +529,6 @@ export class DataService {
       })
       .pipe(
         map((response) => {
-          if (response.summary?.firstOrderDate) {
-            response.summary.firstOrderDate = parseISO(
-              response.summary.firstOrderDate
-            );
-          }
-
           if (response.holdings) {
             for (const symbol of Object.keys(response.holdings)) {
               response.holdings[symbol].assetClassLabel = translate(
diff --git a/libs/common/src/lib/interfaces/portfolio-summary.interface.ts b/libs/common/src/lib/interfaces/portfolio-summary.interface.ts
index 5b27f4c7..42496b22 100644
--- a/libs/common/src/lib/interfaces/portfolio-summary.interface.ts
+++ b/libs/common/src/lib/interfaces/portfolio-summary.interface.ts
@@ -16,7 +16,6 @@ export interface PortfolioSummary extends PortfolioPerformance {
   filteredValueInBaseCurrency?: number;
   filteredValueInPercentage?: number;
   fireWealth: number;
-  firstOrderDate: Date;
   grossPerformance: number;
   grossPerformanceWithCurrencyEffect: number;
   interest: number;