Get a jump start on the US trading day with Matt Miller and Dani Burger on "Bloomberg Open Interest." Apple’s era shifts as Tim Cook steps down after 15 years, with John Ternus set to take over. And Kevin Warsh faces Capitol Hill in a high-stakes Fed showdown. We'll take you to Capitol Hill. Plus, UnitedHealth rebounds with higher premiums despite shrinking enrollment, and airlines juggle strong demand against rising costs—how long can travelers keep footing the bill. Bloomberg's Ike Swetlitz