What is Interest on cash?

Interest on cash is what a platform pays on money that is sitting in the account rather than invested. It turns idle balance into a small return, and the rate decides how much that idle balance is actually worth.

The rates in this group vary widely. Backpack leads with 6.5%, well ahead of Acorns Checking at 3.59%. Betterment and Cash App Cash Card sit at 3.5% and 3.5%, while BUX pays the least at 2%.

The figure is one reason to keep cash balances with the platform rather than idle, though a savings account is worth comparing against.