Uncertainty surrounding expected auto tariffs from the Trump administration wiped away most of this week's gains. A.I. stocks were slammed the hardest, seen in Nvidia's (NVDA) 6% sell-off. Arm Holdings (ARM) took a big hit after Qualcomm (QCOM) accused the company of antitrust practices. One notable winner today: Dollar Tree (DLTR), which plans to sell its Family Dollar business for $1 billion. Caroline Woods turns to the biggest stories of the trading session.