The S&P 500 ended a choppy session nearly unchanged, with megacaps like Nvidia and Amazon dragging the index lower. Investors are closely watching earnings reports from major companies like Apple, Meta, and Amazon, which could provide crucial insights into the impact of trade tariffs on future profits. With geopolitical risks and uncertainties in U.S.-China relations, the market remains volatile as investors await key economic data, including the U.S. payrolls report on Friday.