The Federal Reserve released hundreds of pages documenting how bank supervision and regulation failed to prevent the lender’s painful collapse. The F.D.I.C. released a separate report on Signature Bank’s failure.

Federal regulators blame banks' poor management, while U.S. Senators this week sharply questioned oversight after Silicon Valley Bank and Signature Bank failures rattled the financial system.

Two weeks after the bank failed, the fallout has hit the start-up market as investors pull back further.

The picture that is emerging of SVB is one of a bank whose leaders failed to plan for a realistic future and neglected looming financial and operational problems, even as they were raised by Fed supervisors.