diff --git a/app/service/trade_service.py b/app/service/trade_service.py
index 9f30deb..c600c73 100644
--- a/app/service/trade_service.py
+++ b/app/service/trade_service.py
@@ -202,7 +202,7 @@ class TradeService:
         except (AttributeError, ValueError):
             raise SuitabilityMismatchError(
                 f"产品 {getattr(product, 'product_code', '')} 风险等级无效，交易已拒绝"
-            )
+            ) from None
         decision = await evaluate(
             SuitabilityToolInput(
                 customer_id=str(customer_id),