diff --git a/backend/app/services/trade_executor.py b/backend/app/services/trade_executor.py
index 0f4e8e1..56a59a2 100644
--- a/backend/app/services/trade_executor.py
+++ b/backend/app/services/trade_executor.py
@@ -70,6 +70,11 @@ async def _mcp_validate_buy(stock: dict) -> tuple:
 
 
 async def execute_auto_trade_background(recommendations_response: dict, db: AsyncSession):
+    # recommendations_response should be a dict containing 'recommendations_by_rule'.
+    if not isinstance(recommendations_response, dict):
+        logger.error("recommendations_response is not a dict: %r", recommendations_response)
+        return
+
     try:
         trade_results = []
         total_processed = 0
@@ -87,7 +92,20 @@ async def execute_auto_trade_background(recommendations_response: dict, db: Asyn
         
         unique_stocks = {}
         for rule_group in recommendations_response.get("recommendations_by_rule", []):
-            for stock in rule_group["stocks"]:
+            # make sure we have a dict with expected keys
+            if not isinstance(rule_group, dict):
+                logger.warning("Invalid rule_group in recommendations_response: %r", rule_group)
+                continue
+            stocks_list = rule_group.get("stocks")
+            if not isinstance(stocks_list, list):
+                logger.warning("Invalid stocks list in rule_group: %r", stocks_list)
+                continue
+
+            for stock in stocks_list:
+                if not isinstance(stock, dict):
+                    logger.warning("Skipping non-dict stock entry: %r", stock)
+                    continue
+
                 stock_code = stock.get("stock_code")
                 if stock_code not in unique_stocks:
                     unique_stocks[stock_code] = stock
@@ -100,6 +118,11 @@ async def execute_auto_trade_background(recommendations_response: dict, db: Asyn
         )
         
         for stock in sorted_stocks[:max_trades]:
+            # ensure stock is a dict before proceeding
+            if not isinstance(stock, dict):
+                logger.warning("Skipping invalid stock entry in sorted_stocks: %r", stock)
+                continue
+
             try:
                 stock["_position_multiplier"] = position_multiplier
                 stock["_regime_str"] = market_regime.get("regime_200d", "bear") if market_regime else "bear"
@@ -112,11 +135,12 @@ async def execute_auto_trade_background(recommendations_response: dict, db: Asyn
                 await asyncio.sleep(0.5)
                 
             except Exception as e:
+                # stock is dict so we can safely access get
                 logger.error(f"Error executing auto-trade for {stock.get('stock_code')}: {e}")
                 continue
         
     except Exception as e:
-        logger.error(f"❌ Background auto-trade error: {e}")
+        logger.error(f"❌ Background auto-trade error: {e} - recommendations_response={recommendations_response!r}")
 
 
 async def _background_sync_portfolio():