In these volatile conditions, the currency market is a good signal for where stocks are going, and investors should pay attention to it, Dennis Gartman, founder of the Gartman letter, told CNBC.
The yen's moves indicate to what extent investors are willing to borrow money at low rates in Japan and invest it elsewhere.
"The currency market is driving everything, it is almost leading where the capital markets are going," Gartman said.
But the volatility is so high that no clear upturn can be forecasted, and a Dow rally to 11,000 would still be a bear rally, he added.
The dollar and the euro will eventually reach parity, as the single European currency is still fragile, Gartman said.
"This is the first major recession and I'm telling you, at the periphery you got problems in Europe that are now coming to the fore," he added.
Germany, the world's biggest exporter, will soon complain that the currency is too strong while weaker and smaller economies need a strong euro, Gartman said.
Asked where he is investing in the current conditions, Gartman said he was "trading more stocks, trading a few currencies… I tell the two men who are trading my account, guys, keep it low. I can't take that kind of volatility." His portfolio is up 2.5 percent for the year.