Hedge fund titan Marc Lasry speaking at the ICV Manhattan conference, saying the market is experiencing a "sugar high" that has generated a lot of excitement among investors.
The Trump-induced rally has resulted in a better than 8 percent gain in the Dow Industrials since the election.
But before you break out the champagne, Lasry says there are still questions as to whether this rally can continue. As we know, breakthrough moments can be unpredictable.
Lasry, who supported Hillary Clinton, is cautiously optimistic.
"The people [Trump] is putting in place … it will be a big experiment. All those business folks will be able to reduce regulation, increase GDP growth," he said in an interview Thursday with CNBC. "If it occurs, great. I don't know if that happens. … I hope it does. The early signs are positive, so let's wait and see."
The CEO of Avenue Capital Group, which has about $11 billion in assets under management, admitted that even though his firm saw Clinton winning, he didn't set up his portfolio that way.
"So I think we ended up having a huge benefit over the last month," he said.
Going into 2017, Lasry said the main metric to watch is headline growth.
"If you have tax cuts, a much larger deficit in a rising rate environment, that is not beneficial unless you have 3 or 4 percent GDP growth. So what you're going to have is inflation. Question is, what will happen with GDP growth? If it is 3 to 4 percent, that will be very positive," said Lasry.
President-elect Donald Trump's pro-business agenda has been cheered by investors and has been seen as the main driver behind stocks. Energy is currently the best performing sector in 2016 and has risen more than 23 percent.
Lasry said the market would have probably not rallied as much had Clinton won the presidency.
"I think the market would have gone up a little, but a lot of it was priced in," he added.