Your portfolio made 8% over a year. A headline says stocks made 12%. Did you do a bad job?
The missing number is 40%. Before the year began, you assigned that share of your portfolio to bonds and cash. Only 60% was meant to be in stocks.
The headline compares your whole account with one part of its plan. A fair comparison asks what an alternative with the same job would have earned.
A benchmark needs the same job
A benchmark is a yardstick for judging investment performance. Your investment mandate is what the portfolio is meant to own and accomplish. The benchmark follows that job.
Match the asset classes, geography and company sizes in your plan. A US large-company stock index covers only one part of a plan that also includes foreign shares, bonds and cash. A familiar name does not make a fair comparison.
A strategy benchmark also differs from your personal goal. You can beat it and still fall short of the money needed for a down payment or retirement. Winning the comparison does not pay the bill.
Build the comparison before the result
A policy benchmark combines yardsticks for each asset class in the proportions your plan sets in advance. Start with $100,000: 60% broad US stocks, 30% US investment-grade bonds and 10% cash. Investment-grade bonds have higher credit ratings.
A matching fund stands in for each benchmark slice. Your account can hold different investments.
These made-up, one-year returns include reinvested income and deduct fund expenses, with no other fees. No money enters or leaves the account, and there are no trades between slices. Returns are in US dollars, before personal taxes and inflation.
Each slice's contribution is its weight multiplied by its return, measured in percentage points.
| Slice | Weight | Return | Contribution |
|---|---|---|---|
| Stocks | 60% | 12% | 7.2 points |
| Bonds | 30% | 2% | 0.6 points |
| Cash | 10% | 4% | 0.4 points |
The one-year benchmark return is the sum of those contributions: 0.60 × 12% + 0.30 × 2% + 0.10 × 4% = 8.2%.
That benchmark turns $100,000 into $108,200. Your account's time-weighted return of 8.0% leaves $108,000, a $200 shortfall.
Your benchmark-relative return is your account's return minus the benchmark's: 8.0% − 8.2% = −0.2 percentage points. That is the fair gap to investigate.
Against stocks alone, you appear to trail by 4 points. The two shorter bars show how much that comparison overstates the shortfall.
The benchmark follows your policy, not every change in your holdings. If you choose to hold extra stocks midway through a year, that decision belongs in your result. Changing the benchmark to match would hide the effect of your choice.
For a longer comparison, the blend needs a reset rule. Returning it to 60/30/10 at each year-end differs from letting the weights drift as investments grow at different speeds. The component funds or indexes, starting weights and reset schedule all belong in the plan before the results arrive.
Put both returns on the same clock
Time-weighted return keeps the size and timing of your deposits and withdrawals from driving this strategy comparison. A money-weighted comparison needs a benchmark calculation using those same cash flows on the same dates. Comparing your money-weighted return directly with an index's time-weighted return mixes two different questions.
Use total returns on both sides, with the same reinvestment treatment, dates and currency. Over several years, compare cumulative returns with cumulative returns, or annualize both. Leaving dividends out of the benchmark gives your account a head start it did not earn.
A standard market index leaves out the fees you pay to invest. An index fund is an alternative you can buy; its return reflects fund expenses and tracking differences. Separate account or adviser fees can still reduce what you keep. The comparison needs to say which costs are included and whether it is before personal taxes.
If the mandate changes, a new benchmark can start from that date, with the reason explained. Switching to whichever index just did worse moves the finish line after the race.
A good streak is not a verdict
One winning year is weak evidence of skill. Five or ten years do not automatically settle it either. One style of stock can stay in favor for years. Owning more of those stocks can look like repeated good judgment even when the same bet explains the whole streak.
A return gap tells you what happened. Judging skill takes more. Look at whether the advantage survived costs and different market conditions, or rested on a few winning holdings. The calendar alone cannot explain a winning streak.
Volatility and beta help examine the portfolio's swings and sensitivity to the market. Beating a benchmark by taking bigger risks does not, by itself, establish skill. Giving yourself all the credit for a win invites overconfidence, an inflated view of your ability.
For this plan, the comparison fits in three lines of your investment policy, settled before the year starts:
- Scope: The whole account, including cash, against its 60/30/10 plan.
- Yardstick: A named fund for each slice, reset to those weights at each year-end.
- Measurement: The same full year in US dollars: time-weighted total returns with income reinvested, after fund expenses and before personal taxes.
The yardstick is settled before you know whether you like the answer.
In short
- A fair benchmark does the same job as the portfolio.
- Its components, weights and reset rules belong in the plan before the results arrive.
- Return gaps mean little until the dates, currency, income and measurement methods match and costs are clear.
- Beating a benchmark proves neither investing skill nor that you have enough for your goal.