diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0ee1f0c04..69be6319b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Optimized the portfolio calculations with smarter cloning of activities
 - Integrated the add currency functionality into the market data section of the admin control panel
 - Improved the language localization for German (`de`)
 - Upgraded `prisma` from version `5.19.1` to `5.20.0`
diff --git a/apps/api/src/app/portfolio/calculator/twr/portfolio-calculator.ts b/apps/api/src/app/portfolio/calculator/twr/portfolio-calculator.ts
index fba0ead84..3b64cd185 100644
--- a/apps/api/src/app/portfolio/calculator/twr/portfolio-calculator.ts
+++ b/apps/api/src/app/portfolio/calculator/twr/portfolio-calculator.ts
@@ -180,10 +180,10 @@ export class TWRPortfolioCalculator extends PortfolioCalculator {
     let valueAtStartDateWithCurrencyEffect: Big;
 
     // Clone orders to keep the original values in this.orders
-    let orders: PortfolioOrderItem[] = cloneDeep(this.activities).filter(
-      ({ SymbolProfile }) => {
+    let orders: PortfolioOrderItem[] = cloneDeep(
+      this.activities.filter(({ SymbolProfile }) => {
         return SymbolProfile.symbol === symbol;
-      }
+      })
     );
 
     if (orders.length <= 0) {