Group 1 - Regional bank Zions experienced a 12% decline in shares after announcing a $50 million charge related to loans from two borrowers facing legal actions, citing misrepresentations and contractual defaults [2] - Another regional bank, Western Alliance, saw a 10% drop in shares after filing a lawsuit alleging fraud by a borrower who failed to provide collateral for a loan [2] - The KBW Regional Banking Index (KRX) fell by 6.3%, marking its worst one-day decline since April 10, when it dropped 6.4% [3] Group 2 - Several regional banks, including KeyCorp, M&T Bank, and Commerce Bancshares, reported earnings and experienced declines between 5% and 6% [3]