Let's say I want to see what the holding result what be like when SMA30 just starts to go above SMA250 and shows a cross. I created a filter for that and try to run it with Alphalens and changed quantiles to 2 (because there's only true and false). I feed one year data of Q500US. What shows up is the common error "max_loss (35.0%) exceeded 100.0%, consider increasing it."
I'm wondering if Alphalens works on filters at all? Or shall i just try to increase the data period so it has more data?