The Federal Reserve is signaling that the coronavirus disruptions that hit financial markets in March indicate prime money market funds and other sources of short-term funding may need tougher rules.

"The runs on prime money funds and commercial paper were particularly disappointing," Fed vice chairman of supervision Randal Quarles said in prepared remarks for a Thursday speech. He added that "it is worth asking whether there may be other steps needed to secure these very important sources of liquidity."

Quarles, speaking at an Institute of International Finance event, also said that this year's tumult raises questions about whether regulations imposed on money market funds after the 2008 financial crisis "fell short." Quarles said the Financial Stability Board (FSB), a group of global financial regulators he heads, will be examining this issue.