diff --git a/HTS_etf.py b/HTS_etf.py
index 751cea2..cfed4dd 100644
--- a/HTS_etf.py
+++ b/HTS_etf.py
@@ -192,6 +192,8 @@ class HTS_etf (HTS):
 
                     result_5 = self.makeTickData(result, mins=5)
                     result_30 = self.makeTickData(result, mins=30)
+                    if len(result_30['time']) < 100:
+                        continue
 
                     data = self.buySellChecker.analyze(result)
                     data.drop(data.index[:len(data) - analyzed_day], inplace=True)