Let me tell you one thing about interest earnings for banks.
You see only the rich will make money while the common plebians like us gets the offer of .01%
So back in the days that I worked for corporate prime bank, some cash sweep savings is what they earn daily when they cash out their investments portfolio at the end of the trading day. Some people earn the 1% while others earn the 5% rate. The 5% rate was exclusive only to a few certain inside portfolios. It's goofy, cuz even with all the trading that's done, at the end of the day, the cash sweep is the prime money maker for those portfolios. Not all accounts are like that, cuz the good portfolio managers do actually earn money on their investments, while the shoddy ones don't. And there's a whole lot more shoddy ones than good earnings ones.