US small caps are set for a long run of outperformance, since their 10-year return gap versus large caps has turned negative only in technology booms, each followed by big small-cap runs. After the space-race trough they reached an 18% annualized lead by 1983; after the dotcom trough they led by 8-9% into the mid-2000s. They were cheaper than now only at the dotcom peak. Though up about 20% in 2026, they sit near the widest gap in decades. The call fails only if AI keeps all money in ten names. x.comÂ