U.S. stock futures experienced significant declines overnight, with the S&P 500 futures dropping as much as 2% and the Nasdaq 100 futures falling up to 2.7%. European markets also opened lower, with Germany's DAX index falling 2% to 21,295.81 and France's CAC index declining 2.1% to 7,786.32. The downturn was attributed to concerns over newly imposed tariffs, which also led to a sharp decline in Nvidia's stock, dropping over 6.5% and entering bear market territory, down 27% from its all-time high. Other major tech stocks like Apple, Broadcom, Amazon, Palantir, and Tesla also saw declines ranging from 3% to 5% in pre-market trading. Specifically, S&P 500 futures were down 1.7%, Nasdaq futures were down 2.1%, and WTI oil rose 2%. Nvidia's stock was down 25% from its all-time high before further declining to 27%. Apple, Broadcom, Amazon, Palantir, and Tesla stocks fell by 4%, 5%, 3%, 5%, and 5% respectively.