The head of the U.S. Securities and Exchange Commission said his agency and other regulators are keeping taps on emerging risks in the fast-growing corporate debt market, highlighting assets that could he susceptible to liquidity shocks.

Years of low-interest rates and pressure on banks to hold less corporate debt has pushed more of it into investment funds, SEC Chairman Jay Clayton said in prepared remarks at the Economic Club of New York on Sept. 9. The trend isn’t surprising, he said, but the shift away from the regulated banking system has made it more difficult for government watchdogs to monitor...