"I haven't seen action like this since the days of Russian problems back in '97," he said. "These are scary times. I've been trading foreign exchange for a long time. These things frighten me, and I've got to tell you: I'm cutting my positions way down just because of the volatility's so large."
On CNBC's "Fast Money," Gartman said that he had backed off moves of $2 million to $5 million in the yen trade, opting for smaller $500,000 to $1 million "just to keep the volatility to something that is reasonable."
"I mean, these are very scary times," he added.
(Read More: 'The Problem Is the Dollar,' FX Pro Says)