White House chief economic advisor Gary Cohn predicted Wednesday the stock market's big run since the November 2016 election will march even higher.

"I don't think a lot of the tax reform is in the stock market," Cohn said in an Axios interview.

"If you look at what the tax plan is going to do, I don't think it is factored in," he argued. "So I think there is a lot more momentum in the stock market."

Cohn, formerly the No. 2 executive at Goldman Sachs, noted the stock market's price-to-earnings multiple isn't that expensive relative to the economy's fundamentals.

"The stock market is reflecting the reality of what's going in the business environment today," said Cohn, director of the National Economic Council. "There is going to be a continuation [of the] rally in the equity markets based on real underlying fundamentals of the U.S. economy ... as well as companies having more earnings power because of lower tax rates."

Cohn also predicted companies will invest more in their business and hire more workers as a result of the tax reform bill.

As of Tuesday's close, the rallied 25 percent since the election on Nov. 8, 2016, when Donald Trump won the presidency.