Bugfix/fix exception when fetching top holdings in Yahoo Finance service (#6279)

* Add missing guard

* Update changelog

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Upgraded `stripe` from version `20.1.0` to `20.3.0`
 
+### Fixed
+
+- Fixed an exception when fetching the top holdings for ETF and mutual fund assets from _Yahoo Finance_
+
 ## 2.235.0 - 2026-02-03
 
 ### Added

apps/api/src/services/data-provider/data-enhancer/yahoo-finance/yahoo-finance.service.ts

@@ -206,26 +206,26 @@ export class YahooFinanceDataEnhancerService implements DataEnhancerInterface {
       );
 
       if (['ETF', 'MUTUALFUND'].includes(assetSubClass)) {
-        response.sectors = [];
-
-        for (const sectorWeighting of assetProfile.topHoldings
-          ?.sectorWeightings ?? []) {
-          for (const [sector, weight] of Object.entries(sectorWeighting)) {
-            response.sectors.push({
-              name: this.parseSector(sector),
-              weight: weight as number
-            });
-          }
-        }
-
-        response.holdings = assetProfile.topHoldings.holdings.map(
+        response.holdings =
+          assetProfile.topHoldings?.holdings?.map(
             ({ holdingName, holdingPercent }) => {
               return {
                 name: this.formatName({ longName: holdingName }),
                 weight: holdingPercent
               };
             }
-        );
+          ) ?? [];
+
+        response.sectors = (
+          assetProfile.topHoldings?.sectorWeightings ?? []
+        ).flatMap((sectorWeighting) => {
+          return Object.entries(sectorWeighting).map(([sector, weight]) => {
+            return {
+              name: this.parseSector(sector),
+              weight: weight as number
+            };
+          });
+        });
       } else if (
         assetSubClass === 'STOCK' &&
         assetProfile.summaryProfile?.country