diff --git a/scripts/prefetch_ohlcv.py b/scripts/prefetch_ohlcv.py
index 69b67254..8bcbe29d 100644
--- a/scripts/prefetch_ohlcv.py
+++ b/scripts/prefetch_ohlcv.py
@@ -13,7 +13,6 @@ Usage:
 """
 
 import argparse
-import os
 import sys
 import time
 from pathlib import Path
@@ -59,9 +58,9 @@ def main():
     # Summary
     n_tickers = len(data)
     total_rows = sum(len(df) for df in data.values())
-    cache_size_mb = sum(
-        p.stat().st_size for p in Path(args.cache_dir).glob("*.parquet")
-    ) / 1024 / 1024
+    cache_size_mb = (
+        sum(p.stat().st_size for p in Path(args.cache_dir).glob("*.parquet")) / 1024 / 1024
+    )
 
     print(f"\nDone in {elapsed:.1f}s", flush=True)
     print(f"  Tickers cached : {n_tickers}/{len(tickers)}", flush=True)
diff --git a/tradingagents/dataflows/discovery/scanners/insider_buying.py b/tradingagents/dataflows/discovery/scanners/insider_buying.py
index f57825aa..e8af1360 100644
--- a/tradingagents/dataflows/discovery/scanners/insider_buying.py
+++ b/tradingagents/dataflows/discovery/scanners/insider_buying.py
@@ -138,7 +138,6 @@ class InsiderBuyingScanner(BaseScanner):
             logger.error(f"Insider buying scan failed: {e}", exc_info=True)
             return []
 
-
     def _load_recent_insider_tickers(self, suppress_days: int = 2) -> Set[str]:
         """Return tickers recommended as insider_buying in the past N days.
 
diff --git a/tradingagents/dataflows/discovery/scanners/minervini.py b/tradingagents/dataflows/discovery/scanners/minervini.py
index bebcd214..38e6a1bd 100644
--- a/tradingagents/dataflows/discovery/scanners/minervini.py
+++ b/tradingagents/dataflows/discovery/scanners/minervini.py
@@ -60,7 +60,9 @@ class MinerviniScanner(BaseScanner):
             tickers = tickers[: self.max_tickers]
 
         cache_dir = self.config.get("discovery", {}).get("ohlcv_cache_dir", "data/ohlcv_cache")
-        logger.info(f"Loading OHLCV for {len(tickers)} tickers from cache ({self.lookback_period})...")
+        logger.info(
+            f"Loading OHLCV for {len(tickers)} tickers from cache ({self.lookback_period})..."
+        )
         data = download_ohlcv_cached(tickers, period=self.lookback_period, cache_dir=cache_dir)
 
         if not data:
diff --git a/tradingagents/dataflows/discovery/scanners/sector_rotation.py b/tradingagents/dataflows/discovery/scanners/sector_rotation.py
index f292bd93..52bb1e7e 100644
--- a/tradingagents/dataflows/discovery/scanners/sector_rotation.py
+++ b/tradingagents/dataflows/discovery/scanners/sector_rotation.py
@@ -26,6 +26,7 @@ SECTOR_ETFS = {
     "XLC": "Communication Services",
 }
 
+
 class SectorRotationScanner(BaseScanner):
     """Detect sector momentum shifts and find laggards in accelerating sectors."""