diff --git a/hts/BuySellChecker.py b/hts/BuySellChecker.py
index 7b29f08..1f80240 100644
--- a/hts/BuySellChecker.py
+++ b/hts/BuySellChecker.py
@@ -112,6 +112,9 @@ class BuySellChecker:
     def getBuyPriceAndWeight(self, data, data_5, data_30, i):
         buy, weight = -1, -1
 
+        if len(data_5['slow_k']) <= i:
+            return buy, weight
+
         if data_5['slow_k'][i] < 20:
             if data_5['slow_k'][i - 1] < data_5['slow_d'][i - 1] and data_5['slow_d'][i] < data_5['slow_k'][i]:
                 buy = data['low'][i]