Fitch Ratings published "U.S. Money Market Funds: 4Q23" yesterday, which tells us, "Total taxable money market fund (MMF) assets increased by $219.5 billion from September 30, 2023 to December 31, 2023, according to Crane Data. Government MMFs gained $88.6 billion in assets during this period, prime MMFs gained $50.8 billion, and treasury MMFs gained $80.1 billion. Total MMF assets increased by $1.1 trillion in 2023." It continues, "Taxable MMFs increased their exposure to Treasury securities from September to December. Treasury holdings increased by $498 billion from September 30, 2023 to December 31, 2023 while Repo holdings decreased by $275 billion over the same period, according to Crane Data. MMFs' allocation to Treasury securities increased by over $1 trillion over the course of 2023." Finally, the brief adds, "As of December 31, 2023, institutional government and prime MMF net yields were 5.17% and 5.31%, respectively, per Crane Data. Yields increased significantly in 2023 but have remained stable since the last Fed rate hike in July."