diff --git a/stock_monitor.py b/stock_monitor.py
index 96bb7b2..b0efd31 100644
--- a/stock_monitor.py
+++ b/stock_monitor.py
@@ -36,7 +36,7 @@ def check_bollinger_bands(symbol, data):
 
     # 과거 10개 봉에서 ALERT_THRESHOLD 아래로 빠진 적이 있는지 체크
     check = False
-    for i in range(-1, -10, -1):
+    for i in range(-1, -2, -1):
         past = data.iloc[i]
         upper_band = past['Upper']
         lower_band = past['Lower']