"I would go along with that," Mobius said on CNBC's "Closing Bell" when asked about the comments made earlier in the day by Cooperman, a billionaire investor.
"I've said that if [President Donald] Trump is not reelected, the market would go down," said Mobius, founding partner of Mobius Capital Partners. A 20% or 25% drop "is probably possible."
Cooperman, chairman and CEO of Omega Advisors, took issue with what he called Warren's "war on billionaires." He told CNBC that he believes in a progressive income tax structure where rich people pay more. But he said Warren's wealth tax, which calls for an annual 2% tax on wealth of more than $50 million and 3% on wealth over $1 billion, is "baloney."
Mobius has previously suggested that Trump has been a boon for stocks.
In August, Mobius said the U.S. markets would go "haywire" if Trump failed to win a second term in the White House due to the loss of his "business-friendly" policies.
However, Mobius said Wednesday that the Trump administration's trade war with China isn't having a favorable impact on business.
Mobius said that the trade conflict is causing a slowdown in the global economy, adding that he hopes the U.S. and China will come to an agreement soon.
The Warren campaign did not immediately respond to a request for comment.
— CNBC's Maggie Fitzgerald contributed to this report.