I just checked on the weekly return series on the SP500 dating back to January 1950, and I found that in the 3,065 weeks in this series, the % change in the S&P 500 during the course of this week (-9.4% from last Friday through today) is the fourth worst on record. The only weeks that were worse during this period were the week of the crash of ’87 (-12.2% net, inclusive of the more than 20% decline on “Black Monday (October 19)), the week leading up to 9/11 (-11.05%), and the first week of April 2000 (-10.54%).