A hedge fund executive and major Republican donor believes Donald Trump's policies would spell big trouble for the U.S. economy.

Paul Singer, head of $27 billion Elliott Management, said Wednesday that he may not vote for anyone in the race between presumptive nominees Trump and Democrat Hillary Clinton, and joked he is considering writing himself in.



"The most impactful of the economic policies that I recall him coming out for are these anti-trade policies," Singer said during a panel discussion at the Aspen Ideas Festival in Colorado. "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."



Trump has pledged hefty tariffs against nations including China if they don't renegotiate trade policies he says are detrimental to U.S. interests.

Singer supported Florida Sen. Marco Rubio in what was once a 17-person race for the GOP nomination. Singer most recently gave $1 million in April to the Our Principles PAC, which was part of the campaign to stop Trump, according to OpenSecrets.

The Trump campaign did not respond to a request for comment.

See more of Singer's comments today on CNBC's "Closing Bell" from 3-5 pm.