Is the S&P 500’s Best April in 6 Years Built on Shaky Ground?

U.S. equities closed broadly higher on April 30, 2026, with the S&P 500 gaining 1.02% to 7,209.01 and the Russell 2000 leading at +2.21%, capping the S&P’s best monthly performance since November 2020 with a 10.4% April gain. Caterpillar surged 9.87% on a raised full-year outlook tied to data center construction demand, while Eli Lilly jumped 9.7% after reporting Q1 revenue of $19.8 billion — 55.5% above last year — and lifting its 2026 revenue guidance to $82–$85 billion. Technology acted as the session’s primary drag, with Microsoft falling 3.93% and Nvidia losing 3.94% amid analyst skepticism over the ROI on combined capex commitments of $325 billion from Microsoft and Meta.