It's 0.25% higher than the rate they pay for Marcus. I've been a Marcus customer for a few years, and the rates consistently go up (and down) after the Feds change their rates.

Why is the Apple rate higher than the Marcus rate? It could be a higher intro rate, but there's no indication that that's the case. My guess is that they can afford to give an extra 0.25% because they don't need to spend any money on customer acquisition/marketing costs.

Marcus and Betterment often go back and forth on who provides the higher rate. Right now Betterment is 4.2%, so the rate that Apple/GS is providing isn't outrageously high, it's potentially a real rate that can be sustained. It's only outrageously high compared to the 0.01% that many big banks offer.

.. guaranteed for 12 consecutive months.