Wall Street stepped into 2026 with a solid footing after three powerful years of gains. Still, February brought fresh swings. Concerns about the long-term payoff from heavy AI spending triggered a rotation out of technology shares, even as many companies delivered strong earnings. The broader index has moved sideways, but beneath the surface, individual stocks have seen sharp advances and declines, creating a market driven more by stock selection than headlines.

Trade policy has added another layer of uncertainty. After the Supreme Court struck down earlier emergency tariffs, the administration responded with higher global duties, unsettling investors who had hoped for easing tensions. Slower growth at the end of last year and sticky…