Billionaire investor George Soros on Thursday said he shorted the S&P 500 stock index and that it isn't yet the time to buy.

In an interview with Bloomberg Television in Davos, Switzerland, the 85-year-old hedge-fund titan said he had also taken a long position in U.S. Treasurys. The S&P 500 SPX, -0.11% is down 8.6% in the new year, while Treasurys have rallied.

Soros praised central banks for employing quantitative easing, which he credited with avoiding a repeat of the Great Depression. But he added that QE has diminishing returns. He also said he didn't expect the Federal Reserve to further raise interest rates following its decision in December to enact the first hike in nearly a decade.

Soros said the Fed waited too long to hike, missing its "window of opportunity" by about a year and instead "raising interest rates when the U.S. economy is already slowing down" due to deflation.

"The key issue is deflation…We just don't know how to handle it. It's a different environment, but now we have to face it," he said.

Soros said a hard landing for China is "unavoidable" and that the country's policies are contributing to the global deflationary environment.

"China can manage it. It's got resources and a greater latitude in choosing policies than most other countries because it has over $3 trillion of reserves and so on," he said. "However, they have a way of inflicting their problem…on to the rest of the world."

In the interview, Soros repeated his previous warning that the European Union faces a devastating series of crises that threaten its very existence.

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