If interest rates decrease, banks are predicted to hold high-yield savings account rates higher and for a longer duration than brokerage money market mutual funds, causing money market funds to underperform high-yield savings accounts almost immediately.
"as soon as rates go down you'll see the banks will hold their rates higher a little bit longer than the brokerage companies it's going to be almost immediate that those those money market mutual funds will now be underperforming the high yield savings accounts"
