Two reasons. First, TFA states as much: "repo program that provided nearly $20 TRILLION in cumulative loans to Wall Street". Second, the Sep 2019 repo crisis

Two reasons. First, TFA states as much: "repo program that provided nearly $20 TRILLION in cumulative loans to Wall Street". Second, the Sep 2019 repo crisis is well-known, it lasted multiple weeks, and it was big enough that the Fed wrote a postmortem about it: https://www.federalreserve.gov/econres/notes/feds-notes/what-happened-in-money-markets-in-september-2019-20200227.htm https://www.federalreserve.gov/econres/notes/feds-notes/what... You can read the details, but the Fed offered very short-term loans in the range of tens of billions, rolled over for an unusually long time.