Update app.py

app.py

@@ -32,7 +32,7 @@ for company, ticker in TICKERS.items():
     df_prices = yf.download(ticker, start=start_date, end=end_date)[['Close']].reset_index()
     # Flatten multiindex columns if present
     df_prices.columns = [col if not isinstance(col, tuple) else '_'.join(col) for col in df_prices.columns]
-    df_prices['Date'] = pd.to_datetime(df_prices['Date'])
+    df_prices['Date'] = pd.to_datetime(df_prices['Date_'])
     prices[company] = df_prices
 
 # --- MERGE PRICES IN DATASET ---