A liquidity crunch in China could present a headwind for investors, Dennis Gartman of The Gartman Letter said Monday.
"I'm still bullish of stocks. Stocks are going to go higher. But if there's something that I'm concerned about, it is China," he said. "The liquidity crunch is very serious. Usually, these things resolve themselves in a very benign manner. Usually, these problems just disappear after the turn of the year. But if you have to be concerned about something, be concerned about the fact that short-term rates in China have risen several hundred basis points. It's happened in the past. It's going to happen again."
On CNBC's "Fast Money," Gartman said that he was also concerned about the dispute between China and Japan over the uninhabited Senkaku Islands in the East China Sea.
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"Those are concerns that bother me," he added. "I don't think any of them will play out, but it's on my radar screen, and I think people have to pay attention to it."
Gartman reiterated that he was not expecting market dislocation from the concerns over China.
"I'm really not concerned. I think it's going to be a benign resolution," he said. "Our job is to be prepared for those things that come out of the woodwork and surprise you, and this is the one surprise that I think could happen."
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Gartman also echoed an earlier sentiment about believing in "simple things," such as aluminum, ships, railroads, steel, coal and ball bearings.
"I like the simplest things that are incumbent in global economic growth," he said. "But if there's something on the radar that we should be paying attention to, let's pay attention to China."
Asked about Alcoa's recent strong stock performance, Gartman said, "It's one of the reasons why I've been bullish of aluminum."
Alcoa is the second-largest holding in his personal retirement holdings, he added, and he has "written some 10 calls" on the stock.
"Aluminum, zinc and tin are all turning upward," he said. "Pay attention to what's going on there."