Markets closed mostly down, though Nvidia's (NVDA) new all-time high pushed the Nasdaq-100 (NDX) over the flat line. Meanwhile, Boeing (BA) reached a tentative agreement with its striking labor union, an activist investor reportedly took a stake in Kenvue (KVUE), and UPS Inc. (UPS) got a downgrade from Barclays. Caroline Woods takes a look at the day's biggest headlines.