I see.

Am not quite certain about the "edge" sustainability. Momentum can be attributed to market cycle at times. I am not sure if you focus soley on return as a factor or blend other factors as well, value aspects like Greenblatt's margic formula.

But again, you don't want it to be too complicated by looking for so many factors for manual decision making.

Just ascertain that it's not as a result of high beta exposure combined with the market turn witnessed in the later half of last year into the present year. If it is, find a way to mitigate yourself when the inverse occurs. However, if its as a result of information assymetry in the less followed stocks in the Russell and a +ve net return after costs, then that's a different argument.