Chebyshev’s Inequality
The time-weighted rate of return (TWRR) measures the compound growth rate of an investment portfolio. Unlike the money-weighted rate of return, TWRR is not sensitive to withdrawals or contributions. Essentially, the time-weighted rate of return is the geometric mean of the holding period returns of the respective sub-periods involved.
When working out time-weighted measurements, we break down the total investment period into many sub-periods. Each sub-period ends at the point where we have a significant withdrawal or contribution. It could also end after a month, quarterly or even semiannually. We encourage candidates to follow the procedure below when computing TWRR:
Summarily, compounded TWRR = {(1 + HPR1)*(1 + HPR2)*(1 + HPR3)…*(1 + HPRn-1)*(1 + HPRn)} – 1
Finally, annual time-weighted rate of return = (1 + compounded TWRR) 1/n – 1
Where n is the number of years
An investor purchases a share of stock at t = 0 for $200. At the end of the year (at t = 1) the investor purchases an additional share of the same stock, this time for $220. She then sells both shares at the end of the second year for $230 each. She also received annual dividends of $3 per share at the end of each year. Calculate the annual time-weighted rate of return on her investment.
Solution
First, we break down the 2-year period into two 1-year periods:
Holding period 1:
Beginning value = 200
Dividends paid = 3
Ending value = 220
Holding period 2:
Beginning value = 440 (2 shares * 220)
Dividends paid = 6 (2 shares * 3)
Ending value = 460 (2 shares * 230)
Secondly, we calculate the HPR for each period:
$$ \text{HPR}_1 =\cfrac {(220 – 200 + 3)}{200} = 11.5\% $$
$$ \text{HPR}_2 =\cfrac {(460 – 440 + 6)}{440} = 5.9\% $$
Lastly,
$$ (1 + \text{annual TWRR})^2 = 1.115 * 1.059 $$
Therefore,
$$ \text {annual TWRR} = (1.115 * 1.059)^{0.5} – 1 = 8.7\% $$
The money-weighted rate of return is sensitive to the amount and timing of cash flows and could lead to an unfair rating of the fund manager – They have no control over the amount or timing of cash flows. This effect is eliminated by the time-weighted rate of return. The money-weighted rate of return would only be superior to the TWRR if and only if the fund manager had complete control over cash flows and their timings.
Question
A chartered analyst buys a share of stock at time t = 0 for $50. At t = 1, he purchases an extra share of the same stock for $53. The share gives a dividend of $0.50 per share for the first year and $0.60 per share for the second year. He sells the shares at the end of the second year for $55 per share. Calculate the annual time-weighted rate of return.
A. 5.9%
B. 12.24%
C. 7%
Solution
The correct answer is A.
We have two 1-year holding periods:
HP1:
P0 = 50
D= 0.5
P1 = 53
HP2:
P0= 106
D = 1.2
P1 = 110
We now calculate the holding period returns:
$$ \begin{align*}
\text{HPR}_1 & =\cfrac {(53 – 50 + 0.5)}{50} = 7\% \\
\text{HPR}_2 & =\cfrac {(110 – 106 + 1.2)}{106} = 4.9\% \\
\text{Compounded TWRR} & = 1.07 * 1.049 = 12.24\%
\end{align*} $$Therefore,
$$ \text {Annual TWRR} = (1 + 0.1224)^{0.5} – 1 = 5.9\% $$
Reading 7 LOS 7d
Calculate and compare the money-weighted and time-weighted rates of return of a portfolio and evaluate the performance of portfolios based on these measures. (Part two)