America Remembers 9/11: 20 Years Later. Plus, The Market's 4-Day Losing Streak, Pres. Biden's Sweeping Vaccination Push, The Biden-Xi Phone Call, Beijing's Crackdown on Tech, and Affirm Soars - "Buy Now?"

Squawk on the Street - America Remembers 9/11: 20 Years Later. Plus, The Market's 4-Day Losing Streak, Pres. Biden's Sweeping Vaccination Push, The Biden-Xi Phone Call, Beijing's Crackdown on Tech, and Affirm Soars - "Buy Now?"