After three straight days of declines in the major stock indices, it's time to rethink long positions, Dennis Gartman said Monday.
"You should be less long than you have been, and I think you should be demonstrably less long than you have been," the editor and publisher of The Gartman Letter said on CNBC's "Fast Money."
The S&P 500 closed below its 200-day moving average, a key technical level, and the Nasdaq closed 8.6 percent from its September record.
For Gartman, the technical levels were crucial.
"When you start breaking trend lines, when you start closing below 200-day moving averages, when you start closing below 50-week moving averages, when markets open higher (and) close on their lows, when the VIX goes up as it has, when the derivatives markets are showing you that the markets want to go lower, being less long, being less exposed is probably the better place to be," he said.
Gartman said he was largely out of the stock market, with "north of 80 percent in cash and short-term bond funds."
"From a technical perspective, from an economic perspective, this is very disturbing," he added.
Gartman also cited weakness in the U.S. dollar as a negative sign.
"I'm not sure what it is, but it is very disturbing to see the dollar move that hard, that fast and that low," he said. "This is disconcerting."
From his perspective, Gartman said it was "still a bull market" for the dollar.
"What's disturbing is there's every reason that the yen should weaken. There's every reason that we should be trading 110, 115, 120 yen to the dollar. But here we are trading 106½ yen to the dollar," he said. "We were at 109 just three trading sessions ago, so something is going on here. Money is not moving to the United States as we thought it should have been moving in a safe haven."
Gartman said that stocks weren't attractive at the moment.
"Right now, the only place that I feel comfortable is: One, on the sidelines, and two, owning gold in non-U.S. dollar terms," he said. "My trade is to be in cash."
Gartman suggested not ascribing too much to the drop in crude oil prices.
"I don't think that the crude oil market is indicative of economic weakness," he said. "I think the crude oil market is indicative of excessive inventories of crude, and even more coming at us in the fact that the Saudis would like to push crude oil prices down to stop fracking and to do damage to the Iranians and to do damage to the Russians."