Open your money market app and it shows "7-day annualized 2.1%." Put 100,000 in, and will you really earn 2,100 a year? The answer is probably not. That number is a "7-day annualized yield" — neither your actual return over the past year nor a promise for the future. Let's fully decode the two numbers on a money fund's page — the 7-day annualized yield and the 10,000-yuan daily earnings — so you know what your money is really making.
Two Key Numbers: 7-Day Annualized Yield vs. Daily Earnings
Money market funds publish two numbers every day. The 10,000-yuan daily earnings is "how much money 10,000 yuan of principal actually earned today" — for example, if it shows 0.55 yuan, your 10,000 yuan credited 0.55 yuan today. It's a real, received number. The 7-day annualized yield averages the past 7 days of returns and converts them to an annual rate as an estimate — a predictive figure meant for easy comparison across products.
How they relate: the 7-day annualized yield is roughly the average daily earnings over the past 7 days, annualized over 365 days. Formula: 7-day annualized = (cumulative 10,000-yuan earnings over 7 days ÷ 7) × 365 × 100%. For instance, if a fund earned 0.40 yuan per 10,000 yuan cumulatively over the last 7 days, the annualized figure is about (0.40 ÷ 7) × 365 ≈ 2.086%. In short: daily earnings tell you what you earned today; the 7-day annualized tells you the approximate annual level.
| Metric | Meaning | What to Watch | Caveat |
|---|---|---|---|
| 10,000-yuan daily earnings | Actual return per 10,000 yuan today | What you actually received | Floats daily, verifiable |
| 7-day annualized yield | Past-7-day return annualized | Comparing products | An estimate, not guaranteed |
| 1-year return | Actual annualized return last year | Long-run real level | More reliable than the 7-day figure |
How to Calculate the 7-Day Annualized Yield: Step by Step
Suppose a fund's daily earnings per 10,000 yuan over the past 7 days were 0.50, 0.52, 0.48, 0.55, 0.51, 0.53, and 0.49 yuan, totaling 3.58 yuan. First average the 7 days: 3.58 ÷ 7 ≈ 0.5114 yuan per day. Then annualize: (0.5114 ÷ 10,000) × 365 ≈ 1.866%. In other words, if returns stayed at this level all year, 10,000 yuan invested would earn about 1.87% annually.
Here's the key misunderstanding to flag: the 7-day annualized yield is an annualized extrapolation of just the last 7 days. Money fund returns fluctuate with market rates — daily earnings spike when liquidity tightens at quarter- or year-end and dip around holidays — so judging a fund by one day's figure is misleading. A more reliable lens is the 1-year return or yield since inception, which reflects real money received. To model how a balance grows at different yield levels, use the compound interest calculator; to express returns as a percentage of principal, use the percentage calculator.
Using It to Pick a Fund: Three Practical Tips
First, don't judge by the 7-day annualized alone. A high figure on one day says little about the long run — prioritize the "1-year return" and "3-year return," which are the actual scorecard. On the same platform, use the 7-day figure as a hint and the 1-year figure as the basis; a fund strong on both is worth your money.
Second, watch fund size and fees. A fund too small can be hurt by large redemptions; one too large can be slow to adapt — mid-size funds of a few billion to tens of billions are usually the steadiest. On fees, the lower the total expense ratio (management + custody + sales service), the more you actually keep — a 0.3-percentage-point fee gap is 300 yuan a year on 100,000 yuan.
Third, treat it as cash management, not investing. A money fund is a liquidity tool for money you may need soon; yield is a bonus. If your goal is beating inflation and long-term growth, this isn't the vehicle — that's where the long-run compounding logic of the CAGR calculator comes in. In one line: short-term cash to a money fund, long-term money to a real allocation — don't confuse the two. To decide how much goes where, use the percentage calculator to split "cash / stable / growth" buckets before funding each.
FAQ
Q1: Is the 7-day annualized yield my actual return?
No. It's an annualized estimate extrapolated from the last 7 days of returns, not a promise for the coming year. For the real level, look at the 1-year return or yield since inception.
Q2: What does 0.5 in daily earnings mean?
It means every 10,000 yuan of principal earned 0.50 yuan that day. It's real money credited to your account, varies daily, and continues to accrue on weekends and holidays.
Q3: Why doesn't my return match the 7-day annualized figure?
Because the annualized figure extrapolates just the past 7 days, while your actual return follows each day's earnings and is affected by deposit amount, holding days, and how returns are credited. The longer you hold, the closer your result approaches the 1-year return, not any single day's figure.
Q4: How much money belongs in a money fund?
Only short-term cash you may need within 3-6 months or an emergency fund — the goal is liquidity and low risk, not high yield. Long-term money should be spread into bonds, index funds, or other higher-returning assets.