The S&P 500 closed nearly flat Monday after a volatile session, according to Reuters. Megacap losses weighed on the market ahead of critical earnings and economic data week. Nvidia dropped 2.1, and Amazon fell 0.7, dragging on the S&P 500 and keeping the Nasdaq slightly negative. Apple and Meta rose modestly, helping counteract the declines. Investors are bracing for earnings reports from Amazon, Apple, Meta, and Microsoft while monitoring the potential impact of Trump's new tariffs on corporate profits.