What did you actually earn?
The simplest question in investing has more wrong answers than any other. This unit builds the honest calculator, one correction at a time.
Price return vs total return
A stock goes from €100 to €108 over a year: price return +8%. But it also paid €3 in dividends — cash in your account, as real as the price move (Course 1's dividend lesson). Total return: +11%.
This distinction quietly distorts decades of charts. A price-only index chart HIDES every dividend ever paid — and over long horizons reinvested dividends have contributed a major share of stock-market total returns. Compare a price series to a total-return series of the same index and you see two different histories; only the second is what a patient holder actually experienced. (Your Course 3 adjusted-vs-raw lesson was this idea's cousin — always ask WHICH series a chart shows.)
A third correction: the chart is drawn in the instrument's currency and your account is kept in yours. A US fund held from a euro account earns the fund's return times the dollar's move against the euro, and the second factor is as large as the first in many years. Over calendar 2025 SPY rose from 586.08 to 681.92, about 16% in dollars (monthly closes, December 2024 to December 2025, read 7 September 2026). Over the same year the euro rose from 1.0406 to 1.1747 dollars, about 13%. In euros the same fund went from about 563 to about 581, a gain of about 3%. Nothing was lost in the fund; the dollar it is priced in fell. Add "in which currency?" to the honest questions.
Percentages need a base
The second correction: percentage math betrays intuition around losses and gains in sequence. Up 50% then down 50% is NOT back to even — €1,000 → €1,500 → €750. The mean of +50% and −50% is zero; the money says −25%. Sequences of percentages multiply, they don't add — a fact big enough that the whole next lesson is built on it.
The three honest questions
For any return claim, ask: (1) price or total return? (2) over what period — and is it annualized or cumulative? (3) measured from WHICH starting point? (A fund boasting "+120% since inception" may be describing fifteen mediocre years.) Three questions, thirty seconds — most inflated numbers deflate under them.
In the data
Price return and total return sit side by side in a daily price history: the close is the price-only series, the adjusted close has the dividends folded back in. Here is the S&P 500 fund, SPY, on the first and last session of one year:
The last session's two prices are equal; the first session's adjusted close is lower, because every dividend paid during the year has been folded back into the older price. Last over first, minus one, on the close is the price return; on the adjusted close it is the total return, and the gap between the two is the year's dividends.
Try it now
- Compute the total return: bought at €50, now €53, received €2 dividends.
- €1,000 goes +40% then −40%. Final amount? (Not €1,000.)
- Find one "+X% return!" claim anywhere and run the three questions on it.