Dennis Gartman told CNBC's "Futures Now" on Thursday that his gold call last month couldn't have been more off the mark.
"I think the stock market has a little bit further to go on the downside, perhaps another 25 or 30 S&P points," Gartman said on the Aug. 22 episode of "Futures Now." "So if I had 'X' amount of money to put to work, I'd put it to work in the gold market."
What's happened since then? To put it bluntly, that turned out to be dead wrong.
From Aug. 22 to Sept. 12, the S&P added 30 points, while gold slid $40. Overall, the metal underperformed the S&P by about 5 percent.
"Clearly I'm wrong on the gold, and there's no reason to be anything other than truthful about it," Gartman said.
(Read more: 'Pre-emptive selling' pushes gold to 4-week low)
"What's happened? Peace, or whatever, has broken out. And peace—or at least a lessening of the discord—is always bearish of the gold market," Gartman said.
Whereas U.S. military action once seemed likely in Syria, the emergence of a credible diplomatic option has changed the odds completely. And since war-based uncertainty tends to boost gold, the smaller chance of a strike took a serious toll on it.
(Read more: More 'innocent victims' if US strikes Syria: Putin)
Gartman also pointed out that gold had been a crowded trade, saying, "A lot of people were bullish, a lot of people were long."