While I don’t fully understand how it works, I have read and heard several times that Fed has been pumping money(hundreds of billions) into the market through repo market and this has kept markets going so far.

Short for repurchase agreements, the repo market is a complicated, yet important, area of the U.S. financial system where firms trade trillions of dollars’ worth of debt for cash each day. The activities on this market keep the wheels turning on Wall Street and the broader economy.