Fresh fears of mounting credit stress in the U.S. banking system have resurfaced after JPMorgan Chase & Co. (NYSE:JPM) CEO Jamie Dimon issued a stark warning that more financial trouble could be lurking below the surface.

"When you see one cockroach, there are probably more," Dimon said during last week's earnings call, referring to the recent bankruptcies of First Brands—an auto parts maker reportedly under criminal investigation—and Tricolor Holdings, a subprime auto lender.

On Wednesday, just a day after Dimon’s warning, concerns deepened as Zions Bancorporation (NASDAQ:ZION) disclosed a $50 million charge-off tied to two troubled commercial loans from its California Bank & Trust unit.

A day later, Western Alliance Bancorporation (NYSE:WAL) revealed it had filed a fraud lawsuit against a borrower, adding to the sector's unease.

Now, with regional banks and private equity showing signs of strain, Wall Street is bracing for what could be the next major shock to markets.

Why Treasury Bonds Could Make A Comeback As Liquidity Tightens

While many analysts believe these credit issues remain contained, the broader market may still be vulnerable—not because of credit exposure, but because of liquidity.

Savita Subramanian, head of U.S. equity strategy at Bank of America, says regulated banks today are better capitalized and less likely to spark a full-blown credit crisis.

However, she cautions that the S&P 500’s high concentration in a few large-cap ...