From 29e9336baf5fcec963e90e3fe981b3a8e2ede713 Mon Sep 17 00:00:00 2001
From: Chris Ian Fiel <ccfiel@gmail.com>
Date: Fri, 15 May 2026 20:21:25 +0800
Subject: [PATCH] Bugfix/account cash balance calculation for SELL activities
 with fees (#6862)

* Fix account cash balance calculation for SELL activities with fees

* Update changelog
---
 CHANGELOG.md                                      |  1 +
 apps/api/src/app/activities/activities.service.ts | 11 +++++------
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index be6630ae1..d7676efee 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
 
 ### Fixed
 
+- Resolved an issue with the cash balance calculation of an account for `SELL` activities to ensure fees are correctly subtracted
 - Resolved an exception in the portfolio details endpoint when an asset profile is unmatched
 
 ## 3.3.0 - 2026-05-14
diff --git a/apps/api/src/app/activities/activities.service.ts b/apps/api/src/app/activities/activities.service.ts
index 58b9c11a4..821185e11 100644
--- a/apps/api/src/app/activities/activities.service.ts
+++ b/apps/api/src/app/activities/activities.service.ts
@@ -214,19 +214,18 @@ export class ActivitiesService {
     });
 
     if (updateAccountBalance === true) {
-      let amount = new Big(data.unitPrice)
-        .mul(data.quantity)
-        .plus(data.fee)
-        .toNumber();
+      let amount = new Big(data.unitPrice).mul(data.quantity);
 
       if (['BUY', 'FEE'].includes(data.type)) {
-        amount = new Big(amount).mul(-1).toNumber();
+        amount = amount.mul(-1);
       }
 
+      amount = amount.minus(data.fee);
+
       await this.accountService.updateAccountBalance({
         accountId,
-        amount,
         userId,
+        amount: amount.toNumber(),
         currency: data.SymbolProfile.connectOrCreate.create.currency,
         date: data.date as Date
       });