explicitly check for null

apps/api/src/services/data-provider/data-provider.service.ts

@@ -666,12 +666,13 @@ export class DataProviderService {
     } = {};
 
     for (const date in rootData) {
-      if (rootData[date].marketPrice >= 0) {
+      if (rootData[date].marketPrice === null) {
+        continue;
+      }
       data[date] = {
         marketPrice: rootData[date].marketPrice
       };
     }
-    }
 
     return data;
   }