Compound Interest Challenge
12 weeks. Starts Monday, November 9, 2026. Sign up, then come back each week and check off that you met your challenge.
Step 1: Open your Challenge Savings account
Use a separate savings account in your own name just for the challenge, so the money stays out of sight and you won’t spend it.
Capital One 360 Performance Savings
100% online in all 50 states. $0 to open, no monthly fees. Set automatic weekly transfers from your current bank, and open a separate savings account for each goal.
Open at Capital One → See account detailsCapital One Kids Savings Account
Opened jointly by a parent or guardian with a child under 18. No fees, and the parent can set up automatic savings.
Open a Kids account → See account detailsAlly Savings
$0 to open, $0 monthly fee. Name a “bucket” such as “MMM Challenge” inside one account (up to 30 buckets), then set up a recurring transfer.
Open at Ally → See account detailsHow to set it up
- Open the account online in your own name. Kids: a parent or guardian opens it with the child.
- Name it “MMM Challenge” if the bank allows. At Ally, make it a bucket.
- Set an automatic weekly transfer from your current bank for your tier amount, starting Monday, November 9. Adults: $25–$125. Kids: $5–$20.
MMM is not affiliated with these banks and receives no payment for these links. MMM never holds your money; your account is in your name at the bank. Accounts are FDIC-insured up to applicable limits. Rates and terms are set by each bank and can change. Check the bank’s site before opening.
Who’s in this challenge?
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We show first names and last initials, tier names and weekly checkmarks only. We never show amounts or emails. Check-ins are on the honor system.
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For MMM members and members’ children. Not a member yet? Join MMM first.
Educational only, not financial, tax or legal advice. Recognition only: no cash prizes. Tight week? Do the action and skip or lower the deposit; it still counts.