This is the market banks use to make short-term loans to each other. The New York Fed acted after interest rates in the repo market rose to almost 10 percent, well above the Fed's target rate.
The New York Fed claimed its intervention was a temporary measure, but it has not stopped pumping money into the repo market since September. Also, the Federal Reserve has been expanding its balance sheet since September. Investment advisor Michael Pento called the balance sheet expansion quantitative easing (QE) "on steroids."
I mention these interventions to show that the Fed was taking extraordinary measures to prop up the economy months before anyone in China showed the first symptoms of coronavirus.
Now the Fed is using the historic stock market downturn and the (hopefully) temporary closure of businesses in the coronavirus panic to dramatically increase its interventions in the economy. Not only has the Fed increased the amount it is pumping into the repo market, it is purchasing unlimited amounts of Treasury securities and mortgage-backed securities. This was welcome news to Congress and the president, as it came as they were working on setting up trillions of dollars in spending in coronavirus aid/economic stimulus bills.