It would appear that you enter long when the blue line crosses above the yellow macd histogram. And likewise short when the blue line crosses below it. Hold during the flat blue line...
This indicator (like all of them) is lagging and while it may give profit on trends...it will take it all back and more on those ranging conditions...look at the middle of the chart. You will get "whiplash" trading it.
I fear you will be disappointed with the results...but? If you want to try it in demo to prove that fact...knock yourself out. I would not ever try it live.
