Japan Bears Can Come Out Now: Gartman

All signs point to a much lower Japanese yen ahead, Dennis Gartman, editor of The Gartman Letter, said Monday.

Having traded the yen years ago when it was 265 to the U.S. dollar, Gartman said that the idea of Japan's currency going back to 150 "is not that difficult an imaginative leap," limiting the options available to Prime Minister Shinzo Abe.

"Japan had demographic problems that can only be trumped by monetarist activity, by monetarist activist decisions made by the Bank of Japan and by Mr. Abe," he said.

(Read More: An End in Sight for Japan's Turbulent Markets?)

"They have no choice. The yen has to go demonstrably lower. The dollar has to go demonstrably higher. It will take months, if not years, to do it. Be patient."

The Japanese yen traded 98.71 to the U.S. dollar.

On CNBC's "Fast Money," Gartman said that the 150 level wouldn't happen in the next few weeks, or for the next couple of years.

Despite strengthening economic indicators out of Japan, he added that it would take much more good news to reverse the bearish outlook for Japan.

"It was a surprisingly strong number from GDP, I must admit, but they need that kind of continuation, they need numbers like that for years into the future," he said, adding that the only way that could happen was depreciation.

"Clearly, last week has not fun if you were bearish of the yen," Gartman said. "But it's time to start getting back and being bearish of it after the correction we've had. Same with the Nikkei."

(Read More: Japan Revises First Quarter Growth Figures Upward)

Gartman said that several factors pointed to a lower yen.

"Until that trend has been reversed, I'm going to hold to my position, which I've held for a long, long period of time," he added.

Tim Seymour of EmergingMoney.com said that signs were positive for the Nikkei, adding that he was buying it late last week.

"I think you pile back into this trade," he added.

Trader disclosure: On June 10, 2013, the following stocks and commodities mentioned or intended to be mentioned on CNBC's "Fast Money" were owned by the "Fast Money" traders: Dan Nathan is short XLU June 38/36 put spread; Dan Nathan is long CAT July 87.50/80 put spread; Dan Nathan is long FB June/July 25 call spread; Dan Nathan is long AAPL June 14 435/425 put spread; Guy Adami is long C; Guy Adami is long GS; Guy Adami is long INTC; Guy Adami is long MSFT; Guy Adami is long AGU; Guy Adami is long NUE; Guy Adami is long BTU; Guy Adami's wife, Linda Snow, works at Merck; Tim Seymour is long AAPL; Tim Seymour is long BAC; Tim Seymour is long SBUX; Josh Brown is long AAPL; Josh Brown is long XLU.