The change — effective immediately — will reduce capital demands by about 2% overall, the Fed estimated, and will be open for a 45-day comment period.

Speculative-grade borrowers are different because they made a conscious choice to take on more debt in the hopes of generating bigger returns for equity holders. They did this even though they knew it would make them more vulnerable in an economic downturn.

Federal Reserve Chairman Jerome Powell said the central bank will maintain its muscular efforts to support the flow of credit in the U.S. economy as Americans hunker down from the coronavirus pandemic.

With economists fearing high unemployment stemming from the pandemic, the housing finance system is grappling with how it will recoup lost revenue from delinquencies, forbearance plans and other tremors.

The central bank's sweeping actions suggest a cash shortage gripping sectors directly hit by the pandemic. Banks were supposed to be protected by Dodd-Frank but are still vulnerable to a funding domino effect.

The Federal Reserve committed Monday to conducting more asset purchases of Treasury securities and mortgage-backed securities and announced $300 billion in new financing for credit facilities.

Accommodations for borrowers affected by the coronavirus pandemic, such as payment delays and fee waivers, are "positive and proactive actions that can manage or mitigate adverse impacts," the regulators said.

Mark Calabria said Fannie Mae and Freddie Mac are currently equipped to handle elevated delinquencies, but they might need congressional or Federal Reserve help if fallout from the coronavirus persists.

The central bank said it was establishing the Commercial Paper Funding Facility to "support the flow of credit to households and businesses."

The actions include cutting the federal funds rate to between 0% and 0.25% and other steps to ease economic stress from the spread of the coronavirus.