Lots of people are rightly remarking on the savage Dow bounce-back today. After all, at one point in the day the Dow was down 200-plus points, only to turn the corner and close the day up 300-plus points. That’s enough to require a decent whiplash lawyer. Anyway, inquiring minds want to know: Where does today’s snapback rally rank in the great scheme of such things in Dow history back to 1931? To answer the question, I took the last 77 years of trading history, filtered for days that swung at least 1% negative, but then ended the day positive. That produced a list of 962 trading days out of a possible 19,914 days in the entire period.

— Paul Kedrosky: Dow Bouncebacks: A Trip Though the Data