Since 2014, mega-cap stocks have substantially outperformed small-cap stocks. However, today we sit at the widest valuation gap between small caps and large caps in nearly two decades. This doesn’t seem to be a case of simple mean reversion. Rather, there have been several fundamental factors contributing to the performance gulf between large caps and small caps over the past few years—some of which have been more structural in nature, and many of which still exist today.