Rattled Wall Street on Alert After Trillion-Dollar Risk Runup

After two months of market bliss, Wall Street is stirring from its slumber.

First the collapse of First Brands Group and Tricolor Holdings revived long-dormant fears about hidden credit losses. Then, fraud-linked writedowns at Zions Bancorp and Western Alliance — erasing more than $100 billion in US bank share value in a day — stoked concern that the lending stress is more pervasive.