Rate of Return

The percentage change in value of an investment over a period, including income and price changes.

Rate of return is the percentage gain or loss on an investment over a period. It includes both price changes (capital gains/losses) and any cash income paid during the holding period (interest, dividends, rent).

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How To Calculate Rate of Return

A common holding-period return (HPR) formula is:

\[ R = \frac{V_1 - V_0 + CF_1}{V_0} \]

where V_0 is the initial value, V_1 is the ending value, and CF_1 is cash income received during the period.

If you just want the price return (ignoring cash income), set CF_1 = 0.

Compounding And Annualization

Returns compound over time. If you earn R_1 in period 1 and R_2 in period 2, the two-period return is:

\[ (1 + R_1)(1 + R_2) - 1 \]

To convert a return over T years into an annualized (compound) rate:

\[ R_{\text{annual}} = (1+R)^{1/T} - 1 \]

Sometimes you also see log (continuously compounded) returns:

\[ r = \ln\left(\frac{V_1}{V_0}\right) \]

Log returns add across time, which can be convenient for some models and statistics.

Nominal vs. Real Rate of Return

A nominal return includes inflation. A real return adjusts for changes in purchasing power:

\[ 1+R_{\text{real}} = \frac{1+R_{\text{nom}}}{1+\pi} \]

For small rates, a useful approximation is R_real \approx R_nom - \pi.

Expected Return, Required Return, And Discounting

Economists and investors distinguish between:

  • Realized return: what actually happened.
  • Expected return: what you think will happen on average.
  • Required rate of return: the minimum return you demand to compensate for time value of money and risk.

In valuation problems, the required return shows up as a discount rate. Holding cash flows fixed, a higher required return implies a lower present value.

Knowledge Check

### An investment is bought for 100, pays a cash distribution of 2, and is sold for 108 one year later. What is the holding-period return? - [ ] 8% - [ ] 9% - [x] 10% - [ ] 12% > **Explanation:** The return is `(108 - 100 + 2) / 100 = 0.10`. ### A bond has a nominal return of 7% and inflation is 3% over the same year. About what is the real return? - [ ] 1% - [x] 4% - [ ] 7% - [ ] 10% > **Explanation:** A good approximation is `R_real \approx R_nom - \pi = 7% - 3% = 4%`. ### If the required rate of return (discount rate) rises while the expected cash flows stay the same, what usually happens to net present value (NPV)? - [x] NPV falls - [ ] NPV rises - [ ] NPV is unchanged - [ ] NPV becomes zero by definition > **Explanation:** A higher discount rate reduces the present value of a given cash-flow stream. ### You want the constant annual rate that turns an initial value into an ending value over multiple years (a compound annual growth rate). Which concept matches that? - [ ] The arithmetic average of yearly returns - [x] The geometric (compound) average return - [ ] The inflation rate - [ ] The risk premium > **Explanation:** The geometric average captures compounding and is the rate that links start and end values over time.