Suppose your account starts with $10,000. Two years later it holds $18,900. The balance is 89% higher. But you added another $10,000 along the way, with no other deposits or withdrawals.
You put in $20,000 and have $18,900 left: a $1,100 investment loss. Saving made the account bigger; investing left you with less than you put in.
The balance tells you how much you have. A return tells you how the investments performed. Confusing the two can make a losing account look like a winner.
Separate growth from money you added
We are measuring the whole account, including cash. All examples use US dollars before fees and personal taxes, without adjusting for inflation.
An external cash flow is money or investments you move into or out of the portfolio being measured. Moving $200 from your bank into this account is a contribution. Selling a fund and keeping the cash inside, as in the rebalancing example, is an internal trade.
Dollar profit is the ending balance minus the starting balance and new contributions, plus withdrawals. Taking your own money out is not an investment loss: start with $1,000, withdraw $200 and end with $800, and your investment gain or loss is zero.
A cash distribution is money an investment pays its holders; a cash dividend from a stock is one example. Keep that dividend inside the account and it counts as investment income, not a new contribution.
Count price changes and income
Holding-period total return combines price change and income over the time you hold an investment, as a percentage of its starting value. With no external flows, the one-share calculation is:
Harbor Coffee, our fictional coffee business, reports a share price of $58 at the end of year 2 and $66 at the end of year 3. It pays $1.20 per share during year 3.
Hold one share for that whole year and leave the dividend in cash, earning no interest. The two returns are:
- Price return: ($66 − $58) ÷ $58 = about 13.79%.
- Total return: ($66 − $58 + $1.20) ÷ $58 = about 15.86%.
Price return misses $1.20 that still belongs to you. Your ending wealth is $67.20: the $66 share plus $1.20 in cash. You do not have to sell the share to measure its return.
Count income once. Starting with the full $67.20 and adding the dividend again would count it twice. For a published fund or index return, check whether distributions are already included and reinvested. Dividend reinvestment, where that income buys more shares, comes later.
Read a compound annual rate
In a separate account, $10,000 gains 20% in year one and loses 20% in year two, with no deposits or withdrawals. The total-return path is $10,000 → $12,000 → $9,600.
Add the two annual returns and divide by two: (20% − 20%) ÷ 2 = 0%. That is the arithmetic average investment return. Your money still fell 4%, because the 20% loss applied to a larger balance than the 20% gain.
Investment CAGR, short for compound annual growth rate, is the steady annual rate that would turn your starting wealth into your ending wealth, with no external flows. It works backward through compounding.
Here, (9,600 ÷ 10,000)^(1 ÷ 2) − 1 gives about −2.02% a year. Losing that percentage in each of two years would leave you with the same $9,600.
CAGR hides the bumps; it does not erase them or predict next year's return. This endpoint formula cannot separate investment performance from deposits and withdrawals. Plug in a balance boosted by savings and you will give the investments credit for money you added.
Read the deposit dates
The opening account has a different path: say its annual total returns are +10% then −10%. The extra $10,000 arrives exactly at the end of year one, after the gain and before the loss.
The timeline's biggest jump comes from you. Year one earns $1,000 on $10,000; year two loses $2,100 on $21,000. More money lived through the losing year.
Two measures handle that deposit in different ways:
- Time-weighted return (TWR) links the returns between external flows. Here it joins the +10% and −10% periods without giving the second year extra weight for your deposit. It measures the investment path.
- Money-weighted return (MWR) reflects how much you invested and when. The larger balance in the losing year weighs more heavily here. It measures the experience of your dollars.
Neither method counts a deposit as profit. Changing the deposit's size, while keeping those two period returns, would leave TWR unchanged but change MWR.
Suppose your statement calls the 89% balance increase “your return” and lists the deposit without a date. That label cannot tell you how the investments performed.
For an investment comparison, you need a labeled TWR and its start and end dates. To verify it, the missing pieces are the deposit date and account values immediately before and after it. For your own dollars' experience, you need MWR based on dated flows. The dollar result is already clear: a $1,100 loss.
Before comparing with a benchmark, a yardstick for performance, match dates, currency, income and reinvestment treatment, fees and return method. Compare annual rates with annual rates.
Optional: the return calculations
TWR links growth factors: (1 + first return) × (1 + second return) − 1. Here, 1.10 × 0.90 − 1 = −1% over two years. Annualizing gives 0.99^(1 ÷ 2) − 1, about −0.50% a year.
One way to calculate MWR is the internal rate of return (IRR): a compound rate that balances money in, money out and the ending value on their dates. Here, the first $10,000 works for two years; the second works for one.
10,000(1 + r)² + 10,000(1 + r) = 18,900.
The annual rate r that fits is about −3.71%. All three results describe the same two-year account:
| Measure | Result | Period | Question |
|---|---|---|---|
| Cumulative TWR | −1% | Two years | Investment path |
| Annualized TWR | −0.50% | Per year | Comparison rate |
| MWR | −3.71% | Per year | Dollar experience |
For irregular dates, a spreadsheet's XIRR function can solve for an annual rate. Enter the opening value and contributions as negative amounts, withdrawals and the ending value as positive amounts, each with its date. XIRR uses a 365-day year.
Both methods are useful. Their gap alone does not prove poor timing; the behavior gap lesson examines the evidence behind that judgment.
In short
- A larger balance can hide an investment loss when you add money.
- Total return includes price changes and income, counted once.
- CAGR gives the steady annual rate connecting starting and ending wealth with no external flows. An arithmetic average can hide a loss.
- Time-weighted return measures the investment path; money-weighted return measures your dollars' experience. Match methods and periods before comparing.