The Investment Company Institute published its weekly "Money Market Fund Assets" report Thursday, which shows money fund assets plunging by $​175.​8 billion on huge April 15 tax day outflows to $​7.​643 trillion, the biggest weekly drop in history, after increasing by $​8.​0 billion the previous week. (​The second largest drop ever was $​125.​4 billion during the week ended April 16, 2025; the third largest was $​121.​3 billion the week of Sept. 17, 2008; and the fourth largest was $​112.​0 billion the week ended April 17, 2024.) Assets hit a record high $​7.​856 trillion four weeks ago. MMFs have risen in 23 of the last 30 weeks and 31 of the past 39 weeks. MMF assets are up by $​762 billion, or 11.​1%, over the past 52 weeks (​through 4/​15/​26), with Institutional MMFs up $​536 billion, or 13.​3% and Retail MMFs up $​226 billion, or 7.​9%. Year-​to-​date in 2026, MMF assets are down by $​90 billion, or -​1.​2%, with Institutional MMFs down $​86 billion, or -​1.​9% and Retail MMFs down $​4 billion, or -​0.​1%. ICI'​s weekly release says, "Total money market fund assets decreased by $​175.​81 billion to $​7.​64 trillion for the week ended Wednesday, April 15, the Investment Company Institute reported.... Among taxable money market funds, government funds decreased by $​154.​ …