Druckenmiller is riding the 'raging mania' in stocks but expects to sell before year's end

Stanley Druckenmiller
Katie Kramer | CNBC

Stanley Druckenmiller said Tuesday he believes a bubble has developed across a range of assets, although he remains long the equity market.

"I have no doubt, none whatsoever, that we are in a raging mania in all assets. I also have no doubt that I don't have a clue when that's going to end," the billionaire investor said on CNBC's "Squawk Box."

The CEO of the Duquesne Family Office told CNBC on Sept. 9 that he felt the market was "in an absolute raging mania." The S&P 500 has advanced around 23% from the close on that day to Monday's close of 4,188.43.

"We are still long the stock market," Druckenmiller said Tuesday. "We're not as long, nearly as long, as we were four or five months ago. We're still playing the game. We've shifted a lot of our relative bets into commodities, into interest rates, into the dollar."