Live updates: Wall Street watches First Republic Bank

Treasury Secretary Janet L. Yellen finished testifying before US lawmakers Thursday morning as the global financial system struggles for stability, saying the government should reexamine banking rules.

Bank stocks have swung wildly this week since the Treasury Department and the Federal Reserve announced a sweeping intervention Sunday to protect Silicon Valley Bank’s depositors. On Wednesday, the Swiss National Bank said it would provide assistance to the giant multinational Credit Suisse after the firm disclosed problems in its financial reporting — but said the bank still meets regulatory requirements for systematically important banks for now.