What if the rate changes part-way through the month?

Acorns is committed to keeping you well-informed about any alterations to the APY rates applicable to your account(s). We take our responsibility to notify you seriously, and you can anticipate receiving comprehensive notifications.

Upon any changes in APY rates, you will promptly receive an email notification. Additionally, for your convenience, the updated APY rates will be clearly displayed within your Acorns mobile app. This ensures that you have easy access to the most up-to-date information, allowing you to stay on top of your financial assets with ease.

To learn more about APY, check out Learn in your Acorns app by tapping the links below. 
Understanding APY
What happens when interest rates go up or down?

Also check out this YouTube short for more info.