What is a 7-day yield?
The SEC's standardized money-market fund yield: definition, formula, and a worked example from a real filing.
All figures are from the June 2026 month-end Form N-MFP filings (report date ) — money-market funds must file within five business days of month-end. Regulatory data, not live quotes.
The SEC definition
Money-market funds may only advertise a “current yield” computed the way SEC Form N-1A prescribes: the net change in the value of a hypothetical pre-existing account with one share, from seven days of net income, divided by the account's value at the start of the period, then multiplied by 365/7. Income excludes realized gains and losses and is net of fund expenses. Funds also report this figure to the SEC every month on Form N-MFP — which is where every number on this site comes from.
The formula
7-day yield = (net income over 7 days ÷ account value at start of period) × 365 ÷ 7
Effective (compounded) yield = (1 + base-period return)365/7 − 1
A worked example from a real fund
From the June 2026 month-end filings: VMFXX (Vanguard Federal Money Market Fund) reported a 7-day net yield of 3.58% as of .
- Un-annualized, that is a base-period return of 3.58% × 7/365 = 0.0687% over the seven days.
- On a $10,000 balance, that week's income was about $6.87.
- Compounded weekly for a year ((1 + 0.0687%)365/7 − 1), the effective yield would be about 3.64% — slightly above the simple 7-day figure.
Why it differs from APY
Bank accounts advertise APY, which includes compounding; the 7-day yield does not. Comparing a fund's 7-day yield directly against a savings account's APY slightly understates the fund, by roughly the compounding margin shown above (3.58% simple vs 3.64% compounded for VMFXX). The gap grows with the level of rates but is small — a few basis points at current yields.
FAQ
What is a 7-day yield?
The 7-day yield (or 7-day SEC yield) is the standardized rate money-market funds must use to advertise performance: the fund's net income per share over the most recent seven days, divided by the share price, annualized by multiplying by 365/7. It reflects what the fund actually paid over the last week, after expenses, without compounding.
How is the 7-day yield calculated?
Take the change in value of a hypothetical account from seven days of net income (dividends and interest minus fund expenses, excluding capital gains or losses), divide by the account value at the start of the period to get the base-period return, then multiply by 365/7. Example from the June 2026 filings: VMFXX reported a 7-day net yield of 3.58%, which corresponds to a base-period return of about 0.0687% over the seven days.
Is a 7-day yield the same as APY?
No. APY compounds; the 7-day yield does not — it is a simple annualization (×365/7). A fund's "effective" or compounded yield is slightly higher: VMFXX's 3.58% 7-day yield compounds to about 3.64% if the same weekly return repeated for a year.
How often does a 7-day yield change?
Daily — it is a rolling seven-day window. Fund companies publish it each business day. The figures on this site are the month-end values funds report to the SEC on Form N-MFP, filed within five business days after month-end.