I wish to have "statistic interval" less than 0.5h. 
From my experience, market maker with shorter statistic interval and higher frequency of trading can be profitable too. (But you have to get an exchange with 0% maker fee)

Hi all

I set the amount for mArginmaker strategy to 0.04btc.
But the strange thing is, the bot buy 0.04btc, but the next trade it sells 0.039btc instead of 0.04.
Anything wrong with my setting?