re: AMEX HYSA - 4/9/24 just dropped for first time from 4.35% to 4.3%

Most banks just get a wiff of a possible rate cut 20 years from now and they will immediately cut interest rates. But if the Fed raises rates 0.5% it might take a month before a bank raises your interest 0.35%.

Conversely, banks lending rates change in the opposite way. They're super quick to charge you more, but they will drag their feet to charge you less

It really is criminal the way this works out for their customers.