diff --git a/services/ml/app/preprocessing.py b/services/ml/app/preprocessing.py
index a4595ea..26224bb 100644
--- a/services/ml/app/preprocessing.py
+++ b/services/ml/app/preprocessing.py
@@ -60,9 +60,9 @@ def preprocess_candles(
     except Exception as e:
         raise ValueError(f"Candle data validation failed: {e}")
     
-    # Handle missing volume column - fill with 0 if absent
-    if 'volume' not in df.columns:
-        logger.warning("Volume column missing from candle data, filling with 0")
+    # Handle missing or all-null volume column - fill with 0 if absent/empty
+    if 'volume' not in df.columns or df['volume'].isna().all():
+        logger.warning("Volume data missing from candles, filling with 0")
         df['volume'] = 0.0
     
     # Get feature engineering config