10-Year MMA Compounding Reality
Most savers think in terms of monthly interest ($77/month seems modest). But MMA interest compounds continuously — interest earns interest. Over 10 years the power of compounding makes the rate choice matter dramatically more than the monthly numbers suggest.
MMA 10-year growth on $25,000 lump sum at various APY rates
| APY | $25K After 3 Yrs | $25K After 5 Yrs | $25K After 10 Yrs | 10-Yr Total Earned |
|---|---|---|---|---|
| 0.50% | $25,376 | $25,629 | $26,278 | $1,278 |
| 1.50% | $26,145 | $26,945 | $29,093 | $4,093 |
| 3.00% | $27,318 | $29,023 | $33,598 | $8,598 |
| 4.65% | $28,606 | $31,256 | $38,858 | $13,858 |
The Annual Compounding Gap
Leaving $25,000 at a 0.50% traditional bank MMA while the best online MMA pays 4.65% costs $1,038/year in Year 1. By Year 10 the gap widens to $1,247/year because the online MMA account has grown significantly through compounding while the traditional bank account is barely above the original balance.
On $25,000 lump sum: 0.50% MMA earns $1,278 over 10 years. 4.65% MMA earns $13,858 over 10 years. The $12,580 difference is the total 10-year value of choosing the right bank for your MMA — for zero additional risk or effort.
Growing cumulative gap between 0.50% and 4.65% on $25,000
| Year | Balance 0.50% | Balance 4.65% | Cumulative Gap |
|---|---|---|---|
| Year 1 | $25,125 | $26,163 | $1,038 |
| Year 3 | $25,376 | $28,606 | $3,230 |
| Year 5 | $25,629 | $31,256 | $5,627 |
| Year 10 | $26,278 | $38,858 | $12,580 |
Why Every Year of Delay Has a Compounding Cost
Each year you leave MMA savings at a low rate is not just a linear cost — the year’s foregone interest also misses out on compounding in future years. On $25,000 one year’s delay in switching from 0.50% to 4.65% costs approximately $1,038 in Year 1 plus the compound interest that $1,038 would have earned in subsequent years.
- Every year of delay at a low rate has a compounding cost not just a linear annual cost
- Switching MMA banks takes 30 minutes with zero fees at top online banks
- Even moving 50% of savings to an online MMA captures half the benefit immediately
- Annual rate reviews prevent the compound cost from accumulating over multiple years
See the 10-Year Cost of Your Current MMA Rate
Enter your balance and current APY to see how much you will leave on the table over the next decade.