Portfolio Theory Flashcards
What is Standard Deviation?
- A measure of risk and variability of returns
- The higher the SD, the higher the riskiness of the investment
- How much something “flip-flops” around an average
What can Standard Deviation be used to determine?
Total risk of an undiversified portfolio
What is the Exam Tip for Standard Deviation?
- 68, 95, 99% depending if the return is +/- 1, 2 or 3 standard deviations away from the average
Calculate the standard deviation for two stocks given the following returns over 5 years:
A: 10%, 13%, 8%, -2%, 14%
B: 6%, -3%, 4%, -5%, 7%
- Use the Σ+ key to enter each return, then [SHIFT] {SX, Sy] to solve
A: 6.3875%
B: 5.4498%
Stock A is more risky because it has a higher Standard Deviation
How could a CFP Exam question regarding Standard Deviation be phrased?
“Which of the following assets is most risky?”
They are really asking you to calculate the standard deviation and select the asset with the higher standard deviation.
Calculate the total expected return:
Expected Return__Probability of Return
10% 30%
15% 60%
18% 10%
The calculation is simply the sum of all expected returns multiplied by their respective probabilities:
Return = Σ (R X Probability)
Answer: 13.8%
What is Coefficient of Variation?
- Useful in determining which investment has more relative risk when investments have different average returns
- tells us the probability of actually experiencing a return close to the average return
- The higher the CV the more risky an investment per unit of return
Which investment has the highest risk per unit of return earned?
A: STD=12% and Avg Return=10%
B: STD=8% and Avg Return=5%
CV = Standard Deviation / Average Return
A: .12/.08=1.20
B: .08/.05=1.60
B has more risk per unit, don’t assume that just because A has higher standard deviation that it is more risky
When is it appropriate to consider a Normal Distribution?
If an investor is considering a range of investment returns.
When is it appropriate to consider a Lognormal Distribution?
- Not a normal distribution
- When considering a dollar amount or portfolio value at a point in time.
- looking for a trend line or ending dollar amount
Describe positive and negative skewness:
- Positive: tail stretches to the right (mode, median, mean)
- Negative: tail stretches to the left (mean, median, mode)
What is Kurtosis?
- Refers to the variation of returns
What is positive and negative Kurtosis?
- Positive: little variation of returns, high curve peak
- Negative: widely dispersed returns, low curve peak
What is Leptokurtic?
High peak and fat tails (higher chance of extreme events)
What is Platykurtic?
low peak and thin tails (lower chance of extreme events)
What is Mean Variance Optimization?
- Adding risky securities to a portfolio, but keeping the expected return the same
- Finding the balance of combining asset classes that provide the lowest variance as measured by standard deviation