A billionaire hedge fund manager known for contributing huge sums to Republican candidates cautioned Wednesday that Donald Trump’s economic policies effectively guaranteed a depression.

“The most impactful of the economic policies that I recall him coming out for are these anti-trade policies,” Paul Singer said during a panel discussion at the Aspen Ideas Festival in Colorado, according to CNBC. “And I think if he actually stuck to those policies and gets elected president, it’s close to a guarantee of a global depression, widespread global depression.”

Singer is the founder of Elliott Management Corporation, a fund worth $27 billion that specializes in distressed debt acquisitions. A self-described libertarian, he donated $100,000 to the Republican Party in 2015, according to Forbes, and contributed to Sen. Marco Rubio’s (R-FL) failed bid for the presidency.

Singer’s remarks in Aspen came one day after Trump gave two speeches laying out his fervent opposition to international trade agreements and threatening to raise tariffs on the United States’ leading trading partners, including China and Mexico.

According to CNBC, Singer donated $1 million in April to the anti-Trump Our Principles PAC. He said at the conference that he may not vote for anyone in November.

Singer’s criticism of the presumptive GOP nominee shows how Trump has polarized traditional conservative donors.

Billionaire casino magnate Sheldon Adelson said he would support Trump as the Republican Party’s nominee, and The New York Times reported he may spend up to $100 million aiding Trump’s bid.

Industrialists Charles and David Koch will not donate to either Trump or the GOP convention and have instead signaled that they’ll funnel money towards down-ballot candidates.