gmma moving averages, page-2

I'm not sure what GMMA part of your question is but moving average crossovers do work. They get you into a move late and out late but statistically they make money if you use the right time frames. One of the draw backs is over trading causing large brokerage costs and excessive trading. MAV crossovers can be an excellent basis for a trading plan but need something else to refine them and prevent over trading.