Money-market mutual funds (MMMFs) have had a turbulent couple of weeks. On March 18, the Federal Reserve System created a Money Market Mutual Fund Liquidity Facility (MMLF) to "assist money market funds in meeting demands for redemptions by households and other investors." What's the source of the trouble?
The story begins with an investor flight, driven by fears of coronavirus-related corporate defaults, out of private debt and into safer and more liquid Treasury debt. Prices of US Treasury bonds have been pushed way up, dramatically lowering their yields. Three-month US Treasury bonds, as of March