Jim Cramer's Stop Trading! IndyMac Yellow Flag

Beware the pricey regional bank group, Jim Cramer said Monday on CNBC's "Stop Trading!" segment.

Cramer said banks such as PNC (PNC Quote) are trading at premium to big names such as Citi (C Quote) and Bank of America (BAC Quote) in spite of the regionals' significant exposure to possible lending issues. Cramer said he believes lots of regionals have problems similar to the one revealed late Friday by M&T (MTB Quote).

Cramer is also "concerned" about the so-called Alt-A lenders, the companies that made loans to homebuyers with better-than-subprime credit ratings but without full documentation. He said the degree to which loans were made without documentation is a "big black box" that keeps investors from knowing "who a good lender is." He conceded that some companies like IndyMac (NDE Quote) are "seasoned players" who should know better than to chase nonpaying customers, but he stressed that lenders need to "open things up kimonowise" for shareholders to judge for themselves.

Cramer, stipulating that he "loves" Countrywide (CFC Quote) chief Angelo Mozilo, suggested Mozilo cut back on the TV appearances, reasoning that Countrywide stock gets hit every time Mozilo is on.