Trouble at Zions Bancorp and Western Alliance Bancorp have put US regional banks’ preferred shares in the spotlight on concern the sector is poised for a selloff last seen when Silicon Valley Bank collapsed. Most Read from Bloomberg The preferred shares of Zions on Thursday slumped by the most since May 2023 to its lowest in 18 months, while an issue by Western Alliance dropped the most since April 2024. Bid prices signal the securities will fall further on Friday. The lenders said they were the victims ...