Dennis Gartman: "It's still a bull market…“

"Anyone shorting the global stock market stands to make a "fool" of themselves as equities continue to rally, Dennis Gartman, the founder and editor of the "Gartman Letter," told CNBC on Friday.

"It's still a bull market…and if you try to sell it, if you get out of it, especially if you try to go short of it, you make a fool of yourself," Gartman said in a TV interview.

"What I find interesting and relatively amusing is that every smart guy and every smart woman I know…keeps trying to sell it short, and they put forth wonderful ideas about why stocks are overvalued… but the stock market keeps moving higher," Gartman said.

Gartman warned that investors should be worried about the price of oil following a deal earlier this week with Iran on limiting nuclear activity in exchange for lifting economic sanctions.

The lifting of sanctions is expected to see a surge in Iran's oil output – adding to a market already flooded with supply and putting further downward pressure on oil. "Now that the Iranians are going to be selling crude into the world market on a more aggressive manner it angers the Saudis… who are going to do everything within their power to make certain that they retain their market share," Gartman said.