Bitcoin will trade under $5,000, warns Dennis Gartman

There seems to be nothing that can convince Dennis Gartman to turn bullish on bitcoin.

Despite tanking this month, bitcoin has still soared over 1,400 percent this year. But Thursday on CNBC's "Futures Now," The Gartman Letter editor and publisher reiterated his skepticism on bitcoin's meteoric rise, a view he has held for the past few months.

"I'm very bearish on bitcoin, I think it's one of the silliest ideas I've heard in a long time," he said. "To be separated from the brilliance of the block chain, [makes even] tulips in [17th] century Holland look almost like a quiet, well-demeanored market," Gartman said, using a frequently invoked analogy of the boom in tulip prices that sent the Dutch into a frenzy nearly 400 years ago.

After reaching spectacular heights, tulip prices eventually tumbled sharply. The phenomenon has since become synonymous with bubble markets like 90s dotcom stocks, and housing prices prior to the 2008 financial crisis.

Gartman told CNBC that bitcoin will not only burn all those involved with it, but once it does there will be a rush into gold.

"When bitcoin falls, and it shall, it'll trade under $5,000," he said. "Whether it does it next week, next year, six months from now, it'll happen. And then I think we'll find at the margin money that had moved into bitcoin and away from gold will move away from bitcoin and into gold."

Bitcoin has tumbled 6 percent this week, the latest plunge due to South Korea's possible actions to crack down on the cryptocurrency.