Yellen: stress tests are one tool but supervision of banks is critical

Treasury Secretary Janet Yellen said on Thursday that stress tests are one tool to measure banks' health after the recent collapse of two large U.S. banks, but supervision of banks is critical.

Yellen also told the Senate Finance Committee that stress tests focus on capital, not on liquidity - which was the underlying problem of the bank failures. She also supports tailoring bank supervision to the institution.