diff --git a/config/bollmaker.yaml b/config/bollmaker.yaml
index ac42aeed7..5ecc67315 100644
--- a/config/bollmaker.yaml
+++ b/config/bollmaker.yaml
@@ -200,6 +200,9 @@ exchangeStrategies:
     # buyBelowNeutralSMA: when this set, it will only place buy order when the current price is below the SMA line.
     buyBelowNeutralSMA: true
 
+    # emaCross is used for turning buy on/off
+    # when short term EMA cross fast term EMA, turn on buy,
+    # otherwise, turn off buy
     emaCross:
       enabled: false
       interval: 1h