US stock crashes big today as S&P 500 and Nasdaq fall 0.5%, while Dow drops over 400 points. Markets slipped after PPI inflation rose 0.7% in February. The biggest factor to watch after the US stock crashes big today is the Federal Reserve’s communication. Markets will react strongly to Powell’s tone, especially regarding inflation and future rate cuts. Investors should also monitor oil prices closely. If crude continues to rise, it could further fuel inflation fears and extend market volatility.