Charles,
I do not think this is off topic. My small-cap value strategy has mean-reverted in a big way and this probably could have been used–at least as a hedge–if I shorted in my SEP-IRA.
Edit Had to check. The definition of mean-reversion is not limited to prices as per Investopedia and not limited to negative prices becoming positive: “A reversion to the mean involves retracing any condition back to a previous state.”
It does remain a legitimate question as the whether small-cap value will do well again but I do not see how I could argure that there is no mean-reversion.
Perhaps, people have a particular trading strategy in mind.
Best,
Jim