should have acknowledged that the high beta/vol funds had a roughly 1.6 beta vs the low beta/vol funds of about 0.75, so in a bull market of the last 10 years, the high beta/vol funds should have performed at least (1.6/0.75=) 2.1x better. Since they outperformed by roughly 3.1x better leaves an "unexpected" 1x better outperformance relative to their market sensitivity.