The U.S. banking giant posted better-than-expected revenue and earnings per share for the fourth quarter amid substantial growth in loans, as well as a lighter balance sheet.
Shares of JPMorgan were up moe than 1 percent in morning trading, but had risen nearly 3 percent in the premarket.
"If this stock goes down today, well …," Cramer said, a day after U.S. equities closed in correction territory.
The Dow Jones industrial average ended down 2.21 percent, while the S&P 500 and the Nasdaq composite shed 2.5 percent and 3.41 percent, respectively.
"Yesterday was the day they really took out all the stocks that have been such great performers," Cramer said.
"I think for people who have no money in the stock market, they must've said, 'Hey, maybe this is my chance.' But if you had money in the stock market, you said 'I have to get out.' We're really at a crucial moment."
DISCLOSURE: Cramer's trust did not own JPMorgan's stock when this article was published.