When Business Insider asked Stovall for his best chart of the year, he submitted this pattern that basically predicted this year's huge returns. It comes from a March 25 presentation that his team gave to clients.
It illustrates the annual returns for the S&P 500 during years when it closed positively during the first two months of the year.
On average, the S&P gains 24%.
So far this year, it's up 27%.
That's a breath-takingly small margin of error.
"As always, remember history is a guide, but never gospel," says Stovall.
Check it out.