WaMu Shares Continue Slide

Updated from 3:16 p.m. EDT

Washington Mutual (WM Quote) briefly hit a new 52-week low on Wednesday as concerns continue to mount about the big thrift's potential mortgage losses and the bank gets ready to convert certain preferred stock.

WaMu shares are down 50% since the bank announced a $7 billion capital injection led by private-equity firm TPG and other large investors in early April. But worse, the stock is down more than 20% just from Thursday's closing price, the day before a Wall Street Journal report that said regulators were probing another hard-hit bank from the housing downturn, National City(NCC Quote). The report, confirmed Tuesday by the Cleveland-based bank, has investors worried regulators are looking at other troubled banks.

The bank issued a statement late on Thursday saying that while commenting on market rumors was not its policy, "recurring speculation about regulatory activity" led it to act. ...