diff --git a/src/pages/stock/hooks/usePortfolio.js b/src/pages/stock/hooks/usePortfolio.js
index 1453adc..2bb8d78 100644
--- a/src/pages/stock/hooks/usePortfolio.js
+++ b/src/pages/stock/hooks/usePortfolio.js
@@ -76,7 +76,8 @@ export default function usePortfolio() {
         for (const item of items) {
             const qty = item.quantity ?? 0;
             const purchase = item.purchase_price ?? item.avg_price ?? 0;
-            totalBuy += purchase * qty;
+            // 총 매입 = 종목별 매입가의 단순 합 (수량 미곱산)
+            totalBuy += purchase;
             totalCostBasis += (item.avg_price ?? 0) * qty;
             if (item.eval_amount != null) totalEvalAmt += item.eval_amount;
             else hasNullPrice = true;