Stocks have bottomed, and it's time to go long, Dennis Gartman of The Gartman Letter said Wednesday.
"I own a little bit," he said. "I think it's the right thing to do."
The Dow Jones Industrial Average rallied 149.83 points, or 1.02 percent, to end at 14,910.14. The S&P 500 climbed 15.23 points, or 0.96 percent, to close at 1,603.26. And the Nasdaq bounced 28.34 points, or 0.85 percent, to finish at 3,376.22.
On CNBC's "Fast Money," Gartman said that he was now reversing his previously "agnostic" view on the stock market.
"Yesterday's lows better hold, and I think that they probably shall," he said. "I was really quite impressed by the ability of the stock market to accept a uniquely bad GDP report, second revision of a report that was due six months ago, and it took it very well."
(Read More: Futures Hold Gains After GDP Report)
Gartman also revealed a bit more detail about his positioning.
"Heretofore, I've been long of stock and short of gold, and I've been long of the stock market and perhaps every once in a while trading crude oil against it, but this is the first time I've actually stepped up to own stock indices outright long," he said.