It's the smallest U.S. public companies that are rallying hardest on the prospect of Donald Trump returning to the White House. Markets are expecting a sharp policy shift that could benefit smaller, domestic companies.

Futures tied to the Russell 2000 Index were up 5.7% early on Wednesday, outperforming the Dow Jones Industrial Average and S&P 500.

It's a change in sentiment for the Russell, which has badly underperformed the S&P 500 in recent years, with the latter benefiting from the high-growth artificial intelligence trend and being less influenced by the U.S. economic outlook. The Russell 2000 still hasn't returned to its record highs of 2021.