Treasury Secretary Janet Yellen said Sunday that the federal government would not bail out Silicon Valley Bank, but is working to help depositors who are concerned about their money. The Federal Deposit Insurance Corporation insures deposits up to $250,000, but many of the companies and wealthy people who used the bank — known for its relationships with technology startups and venture capital — had more than that amount in their account. Yellen, in an interview with CBS' “Face the Nation,” provided few details on the government's next steps.