"Nvidia's Earnings Loom, Tech Stocks Drag Market Lower"

U.S. stocks closed lower, with the Nasdaq leading the declines as chipmaker Nvidia's stock stumbled ahead of its upcoming earnings report, causing concerns about justifying its high valuation. Walmart's strong sales outlook pushed its shares to an all-time high, offsetting some of the losses on the Dow Industrials. The broader market was impacted by mixed corporate news, including Discover Financial jumping on Capital One's buyout deal and Smart-TV maker Vizio surging after Walmart's acquisition announcement.