US stocks move in lockstep again, and it's the sharpest selloff in a year

what happened

US equities are moving together again after a long stretch of divergence, but the synchronized move came with the largest selloff in more than a year. Per Dow Jones Newswires, citing MarketWatch, the S&P 500 posted its worst showing since the April 2025 tariff turmoil, and 430 index members closed lower, the most since December 31. The trigger was fear that newly empowered Democrats could slow the data-center buildout.

Trading volume backs up the panic: downside volume on the NYSE topped 80% on Thursday for the first time since November 17, 2025, ending a run of more than 240 sessions without such a reading. BTIG's Jonathan Krinsky called it a major distribution day, a sharp selloff driven by institutional investors.

Krinsky expects one more leg lower before a firmer base forms, and he is watching for signs of capitulation, such as broader deterioration in individual names. According to FactSet, the S&P 500 finished Friday just below 7,400, and he sees it moving closer to 7,000. Piper Sandler's Craig Johnson advises prioritizing capital preservation over buying dips until support holds.

why it matters

The episode shows how a sector-specific policy fear can drag the whole index lower once correlations between stocks normalize. The gap between AI-linked shares and the rest of the market may keep volatility elevated until leadership stabilizes.

market impact

US stocks: broad selloff on data-center policy fears pressures the S&P 500 and AI-linked names

• ▼S&P 500 pressure down — broad selloff driven by fears of curbs on data-center buildout
• ▼US AI stocks pressure down — concern that policy could weigh on data-center demand

instruments

on polymarket