Hi Seahawk, thanks for your comments but I'm not quite sure what you are referring to. The backtest above already uses Interactive Broker's commission structure and assumes basic slippage of $0.01/share. Obviously this is a very basic technical-based strategy that needs to be refined. What this algo is meant to demonstrate is the effect of momentum in GDXJ at an intraday time interval. The fact that using a basic momentum indicator like MACD works so well on GDXJ over such a long time period indicates that there is an underlying price anomaly that causes GDXJ's price to trend consistently. From knowing this, one can further create a better algo to capture this anomaly.
Personally, I've been trading GDXJ with a variant of this algo in our startup's charity fund since March along with XIV and VXX. We use 7 algos altogether and this is one of them. We allocate 15% of the account per algo per trade. Right now, we are up 12% total since inception and trading GDXJ has been the second largest contributor in performance. The trend is your friend ;)
FYI, the bottom contributors are our monthly hedge using SVXY OTM puts.