Your return was 12% — is that good?
Unit closer. You can now compute an honest return — total, CAGR, after the waterfall. One question remains, and without it even an honest number is meaningless: compared to what?
The benchmark idea
A return only acquires meaning next to what was AVAILABLE for the same money, same period, same risk neighborhood:
- +12% while the broad index did +20%? You paid full risk for a partial ride — the market offered more for the same turbulence.
- +12% while the index did +5%? Genuinely strong year.
- +12% while a risk-free deposit paid 11%? One extra point for all that stock risk — the macro course's "why accept stock risk" question answers itself.
The professional habit: every return gets a benchmark — usually a broad index matching what you actually hold (Course 2's index lesson pays off here). No benchmark, no verdict.
The traps around comparisons
Your Course 3 data-literacy kit applies with full force: cherry-picked windows ("since our best year"), survivorship in fund league tables (dead funds vanish from the average), price-return benchmarks compared against total-return claims — same three suspects, new crime scene. And one honest asterisk on ALL past comparisons: last year's winner-vs-index verdict describes last year, not next. History informs; it doesn't promise (nothing here does).
Unit checkpoint ahead
Total return, CAGR, the waterfall, the benchmark — the honest calculator is complete. But two portfolios with the SAME honest return can still be wildly different investments — one a smooth road, one a cliff-edge ride. Measuring that difference is Unit 3's whole subject: risk, finally in numbers.
In the data
The benchmark is a price history like any other, with an index in place of a holding — and it hides this lesson's third trap in plain sight. Here is the S&P 500 index on the first and last session of one year:
On the index, the adjusted close is identical to the close, because a price index has no dividends folded into it. Compare a holding's dividend-inclusive adjusted close against that series and the holding leads by roughly its dividend yield before any skill enters the picture.
Try it now
- Give the verdict: your diversified stock portfolio returned +9%; the matching broad index did +16%. Good year?
- Now run a real comparison and watch the third trap arrive uninvited: the S&P 500 fund, SPY, against the index it copies. Both are below as charts, and to the eye they are the same line: the gap lives in a column, not in the shape. The table under the charts holds the fund's first and last session of the same year as the index table above, 26 September 2025 to 25 September 2026. Compute each return from the adjusted close — last over first, minus one — then subtract. The fund leads, by a little over a percentage point, and it charges a fee, so the sign is backwards from what anybody guesses. On the index the adjusted close is simply a copy of the close, because a price index folds in no dividends; on the fund it collects every one of them. You are looking at a dividend yield wearing the costume of outperformance.
- Run it once more on the raw close of both and the lead vanishes — the fund now trails by a hair, which is the fee and nothing else. Same two instruments, same year, opposite conclusions, and the only thing that changed was which column you read.
- Subtract the fund's dividend yield, the second row below, from the adjusted-close difference. What survives is a few tenths of a point, and it is not skill either: the yield is a year of payouts measured against today's price, which is higher than the price the year started at, and each payout was reinvested for the rest of the year. The honest comparison is the one in step 3, like against like, and there the fund trails by its fee — which is exactly what an index fund promises, and the first comparison in this course that has been fair on both sides.
- Name the three comparison traps from memory — and which course taught you each.
- One sentence: why does "compared to what" outrank "how much" in judging any return?