Sunday (3-15-2020) is the day The Fed got serious about bolstering the U.S. economy facing the coronavirus arrival. Jerome Powell, Federal Reserve Chair, said they will also purchase at least $700 billion in government and mortgage-related bonds. These actions are to keep financial markets stable and borrowing costs low.
The last time The Fed made a step like this was in 2008 which was aimed to bolster the U.S. economy.