MCLEAN, Va., June 30, 2023/PRNewswire/ -- Capital One Financial Corporation (NYSE: COF ) today announced its preliminary?Stress Capital Buffer Requirement ("SCB"), as calculated based on the Federal Reserve's?2023?Comprehensive Capital Analysis and Review process ("CCAR"), is 4.8?percent, effective October 1, 2023. Capital One's?previously disclosed SCB of 3.1 percent, as calculated based on the 2022?CCAR process, will remain in effect through the end of the third quar...