diff --git a/tradingagents/graph/portfolio_analysis.py b/tradingagents/graph/portfolio_analysis.py
index 6409258b..12325e3c 100644
--- a/tradingagents/graph/portfolio_analysis.py
+++ b/tradingagents/graph/portfolio_analysis.py
@@ -181,12 +181,12 @@ class PortfolioAnalyzer:
         directory.mkdir(parents=True, exist_ok=True)
 
         log_data = {
-            "trade_date": str(trade_date),
+            "trade_date": trade_date,
             "tickers": tickers,
             "individual_results": individual_results,
             "portfolio_summary": portfolio_summary,
         }
 
-        log_file = directory / f"portfolio_analysis_{re.sub(r'[^\w.-]', '_', str(trade_date))}.json"
+        log_file = directory / f"portfolio_analysis_{re.sub(r'[^\w.-]', '_', trade_date)}.json"
         with log_file.open("w", encoding="utf-8") as f:
             json.dump(log_data, f, indent=4)