Daily vs. monthly compounding: compare APY first

When one savings account emphasizes daily compounding and another promotes its annual percentage yield, which deserves more weight? Start with the annual percentage yields, or APYs, that apply to your balance. More frequent compounding alone does not establish that you will keep more money. The percentage helps compare interest; fees and qualifications determine whether an apparent advantage survives.14

APY already includes the compounding effect

Compounding means interest earns further interest. The stated annual interest rate excludes that effect, while APY incorporates both the rate and compounding frequency into an annual measure. The Consumer Financial Protection Bureau’s Regulation DD definitions make this distinction explicit. Daily compounding is therefore already reflected in the quoted APY: it is not an extra return to add afterward. Comparing frequency separately as though it supplied another reward would count the same feature twice.12

APY generally assumes no transactions and retained interest; if interest withdrawals are required, its calculation must account for them. Variable rates can change after opening, but without an introductory rate, the calculation holds the initial rate constant for the year.21

An introductory rate is not a full-year return

Appendix A’s regulatory illustration assumes $1,000 and daily compounding: 7% for 91 days, then 5% for 274 days. The lower rate applies for most of the year, drawing the annual yield toward it. The resulting $56.52 interest on $1,000 corresponds to the rounded 5.65% APY. The introductory period follows the contract; the remaining year uses the nonintroductory rate applicable at opening or advertising. That later rate is a disclosure assumption. This is not a current offer or forecast.2

Check the balance rules and fees

Next comes eligibility. A tiered account pays different interest rates at specified balance levels. Select the disclosed APY, or APY range, for the relevant tier. A yield attached to another balance level does not describe what your deposit earns.13

Minimum balances can govern opening, fee avoidance and APY eligibility. Meeting the opening minimum does not establish the other two. Fees may use daily balances during a calendar month, while interest uses the average of daily balances over a statement period. Meeting that average may not satisfy a daily fee-waiver requirement. Disclosures must explain the methods and periods.3

Disclosures also identify maintenance charges, such as monthly service fees, and their triggering conditions. The comparison needs interest and charges expressed in dollars over the same holding period, using the same starting deposit.34

For a full year under disclosure assumptions, the deposit multiplied by APY divided by 100 approximates interest dollars, allowing for yield rounding.2

Then total the applicable charges for that year, including each recurring charge, and subtract them from interest. Compare what remains for each account. A higher APY leaves more only if its additional interest exceeds its additional charges. An annual percentage and one month’s fee cannot answer that question until both cover the same period.4

Changing rates, withdrawals or fees deducted from the balance can change the interest earned.24

In advertising, look for the offer period or date as of which the APY is accurate, the balance qualification and the warning that fees could reduce earnings. Under the tiered-account advertising rule, each minimum balance appears near, and with equal prominence to, its corresponding APY.4

Broadcast ads can omit some disclosures, including the fee warning; its absence does not establish that an account is free. Internet and email ads do not receive that exemption. Verify yield and conditions in account terms. A variable-rate ad’s date does not lock in its yield.4

Compounding, crediting and deposit protection differ

Access adds another distinction: interest can compound daily but be credited monthly. Earning further interest and posting it to the account follow different schedules. Closure before crediting can forfeit accrued—accumulated but uncredited—interest when the contract and applicable law permit it. Withdrawing all funds can count as closure. Withdrawal limits are account-specific terms.23

Before comparing a money market product, establish what it is. A money market deposit account is offered by a bank or credit union. A money market mutual fund is an investment, even if it permits check writing. Similar names and payment features do not make them interchangeable. The deposit-account APY comparison therefore starts with identifying the product, before weighing its percentage or access features. The CFPB advises confirming deposit coverage when multiple accounts are held at one institution.5

The basic FDIC framework is $250,000 per depositor, per insured bank, per ownership category. That is not a separate allowance for every account, and the general framework does not establish anyone’s individual coverage. Deposit protection concerns the protection of deposits if a bank fails. It does not promise an APY or determine the earnings left after account charges.654

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