CNBC's Jim Cramer said the Federal Reserve's emergency interest rate cut on Tuesday morning makes him more concerned about the economic risks from the coronavirus.

"It's great that the Federal Reserve recognizes that there's going to be weakness, but it makes me feel, wow, the weakness must be much more than I thought," Cramer said on "Squawk on the Street."

"I'm now nervous. I'm more nervous than I was before."

The move helps Wall Street but does little to persuade consumers worried about catching the coronavirus to leave their homes and spend their money, Cramer said.

Stock trading around the Fed's surprise rate cut of 0.5% saw the Dow Jones Industrial Average swing from down over 350 points to up over 350 points. The Dow then flop-flopped between losses and gains.

The Dow accelerated to the downside, off more than 900 points at the low, after Fed Chair Jerome Powell's late-morning news conference explaining the reasoning behind the rate cuts. The Dow closed down 785.91 points, or nearly 3%.

The rate cut puts the fed funds target between 1%-1.25%. The Fed reduced rates in three 0.25% moves last year.

Hopes for a Fed cut rate sparked a powerful rally Monday. The Dow soared nearly 1,300 points, or 5%, in its biggest percentage gain since March 2009, reclaiming a big chunk of last week's largest weekly decline since the financial crisis.