"Since the outbreak of COVID-19, the Fed has vastly expanded the scope of its repo operations to funnel cash to money markets. The Fed’s facility makes cash available to the primary dealers in exchange for Treasury and other government-backed securities. Before coronavirus turmoil hit the market, the Fed was offering $100 billion in overnight repo and $20 billion in two-week repo. It ramped up the operations on
March 9, offering $175 billion in overnight and $45 billion in two-week repo. Then, on
March 12, the Fed announced a huge expansion. It is now on a weekly basis offering repo at much longer terms: $500 billion for one-month repo and $500 billion for three months.
On March 17, at least for a time, it also greatly increased overnight repo offered. The Fed said that these liquidity operations aimed to “address highly unusual disruptions in Treasury financing markets associated with the coronavirus outbreak.” In short, the Fed is now willing to loan what is essentially a
What is the repo market, and why does it matter?
Cheng and Wessel explain what repo market is, what happened in repo market in September 2019 and Fed's responses.
https://www.brookings.edu/blog/up-front/2020/01/28/what-is-the-repo-market-and-why-does-it-matter/