The Federal Reserve's approval of the Volcker Rule, meant to rein in risky trading in reaction to the financial crisis, sends a clear signal, bank analyst Mike Mayo of CLSA said Tuesday.
"Banks need to be pillars of strength of stability. They need to facilitate the economy. They need to be a port in the storm," he said. "But no, they can't have a casino inside the bank, so from that standpoint, bank CEOs are put on notice."
(Read more: What you need to know about the Volcker Rule)