The Apple stock has given a return of 36.69 % during the time period discussed.I think that's why the momentum strategy has given a 100% return.I have done the same test with a few other stocks.It didn't fare well.
I have done a backtest for Apple for the time period between Aug and January using vwap of 3 days.I have found these results.It has given 1.07% return compared to the benchmark;s return of 8.24% while the Apple stock's return is -22.61%.
Clearly,this strategy didn't beat the benchmark because the stock's return itself didn't beat it.
I can induce that this strategy can give better returns when compared to the stock but it can beat the benchmark only when the stock beats it.
I will something fishy about my conclusion!