J.P. Morgan is scheduled to report first-quarter earnings before the market opens on April 12. Cramer, host of CNBC's "Mad Money," said the bank has been a "lead dog" of the financials sector, which has risen 10.8 percent this year. J.P. Morgan's stock is up 7.2 percent over that period.
"If that stock doesn't go up when it reports, we're in trouble," Cramer, whose charitable trust owns share of J.P. Morgan, said on "Squawk Box."
Earlier Thursday, J.P. Morgan CEO Jamie Dimon released his annual must-read letter to shareholders. In the letter, Dimon said his bank, the largest by assets in the U.S., is bracing for a possible economic slowdown, though he does not expect a recession.
In recent months, a growing list of economists and business elite has predicted a downturn, as have warning signs from the bond market.
"The key point here is that a fairly healthy U.S. economy will be confronting a wide variety of issues in 2020 and 2021," Dimon wrote. "It's hard to look at all the issues facing the world and not think that the range of possible outcomes is broader and that the odds of bad outcomes might be increasing."
Cramer, who also has said he doesn't expect a recession any time soon, said he's "worried" about Dimon's letter. "The financials are inching up, but if the financials don't catch fire, we can't just do it with semiconductors," he said.