CNBC’s Jim Cramer said Tuesday the market’s snapback has taken many investors off guard, and it’s being fueled by the rush to get back into stocks as emerging evidence indicates that the omicron Covid variant might not be as serious as first thought.

“I think this caught a lot of people by surprise because if you rewind the tape to eight sessions ago you thought that omicron was basically going to spread the same way that delta did. Delta really did set back our economy. So far, that’s not been the case” with omicron, Cramer said on “Squawk on the Street.”

Preliminary data about the severity of omicron is “a bit encouraging,” White House chief medical advisor Dr. Anthony Fauci said Sunday, following the release of early figures from South Africa that suggest it may not be as bad as initially feared.

“Instead what’s happened is the overreaction is so severe both in oil and common stocks that you have this moment where people realize, ‘Wow, we really got oversold. What can I get in. Did I miss the dip?'” the “Mad Money” host said.

The Dow Jones Industrial Average opened roughly 300 points higher and took off from there Tuesday, one day after surging 646 points, or nearly 1.9%. As Cramer pointed out, investors have been growing less worried about omicron. Wall Street, coming off a losing week, has recently been volatile, evidenced by the Dow’s ups and downs since its 905-point plunge on Nov. 26.

— Sign up now for the CNBC Investing Club to follow Jim Cramer’s every move in the market.