David Stockman is warning about the Trump administration's tax overhaul plan, Federal Reserve policy, saying they could play into a severe stock market sell-off.

Stockman, the Reagan administration's director of the Office of Management and Budget, isn't stepping away from his thesis that the 8½-year-old rally is in serious danger.

"There is a correction every seven to eight years, and they tend to be anywhere from 40 to 70 percent," Stockman said recently on CNBC's "Futures Now." "If you have to work for a living, get out of the casino because it's a dangerous place."

He's made similar calls, but they haven't materialized. In June, Stockman told CNBC the could easily fall to 1,600, which at the time represented a 34 percent drop. This week, the index was trading at record levels above 2,500.

Stockman puts a big portion of the blame on the Federal Reserve, and its ultra-loose monetary policy.

"This is a bubble created by the Fed," he said. "We're heading for higher yields. We are heading for a huge reset of pricing in the risk markets that's been based on ultra-cheap yields that the central banks of the world created that are now going to go away because they're telling you that they're done."