Corporate Finance Flashcards
Week 1 Risk Return - What has the highest return if invested $1 in 1900 and valued in 2007?
Portfolio of Treasury Bills
Portfolio of U.S government Bonds
Portfolio of U.S common stock
Portfolio of Treasury Bills: $71
Portfolio of U.S government Bonds: $242
Portfolio of U.S common stock: $14,276
Week 1 Risk Return - Given the following portfolios:
Portfolio of Treasury Bills
Portfolio of U.S government Bonds
Portfolio of U.S common stock
What is can be said about the attributes of each?
Treasury Bills: No default risk and relatively stable prices.
U.S government Bonds: Prices fluctuate with interest rates to remain competitive (bond price down when interest rate up). Newly realeased bonds may have different coupon payments so the existing bonds adjust to remain competitive.
Portfolio of U.S common stock: Risk subject to interest rate changes and the volatile of the stocks.
The higher the risk, the higher the expected return required by investors.
Week 1 Risk Return - r|p|?
The Expected Return from a portfolio of N securities, being the weighted average of expect returns from the single securities in the portfolio.
Week 1 Risk Return - r|p| equation?
w|1| r|1| + w|2| r|2| + … + w|N| r|N|
= Σ w|i| r|i|
where w|i| is the weight of the security in the portfolio and will be the percentage (in decimal terms)
equally be 0.XX, where xx is the expected return.
Week 1 Risk Return - What is the rate of return of a stock? (formula) - CHECK THIS
r = [ { p(t) - p(t - 1) } / p(t-1)] * 100
Week 1 Risk Return - Aside from expected return, what are two possibly equivalent measures of risk?
Variance and Standard Deviation.
Week 1 Risk Return - Variance Formula and interpretation?
σ² = 1/N [Σ (x|i| - μ)²]
The mean of the squared deviations from the mean.
It is a measure of volatility.
If 0, the portfolio is riskless.
Week 1 Risk Return - When talking about the risk of a portfolio, what are we really talking about?
- Idiosyncratic Risk (Stock specific or unsystematic): The risk associated with each individual security.
Systematic Risk (Macro Risk): The degree to which the securities covary, being the covariance between securities.
Week 1 Risk Return - Covariance In terms of the standard deviation and correlation coefficient of two stocks?
σ|12| = ρ|12| σ|1| σ|2|
σ|12|: the Covariance of the two securities.
σ|i|: the variance of security i.
ρ|12|: The correlation coefficient between security 1 and 2.
Week 1 Risk Return - Given the covariance definition “ σ|12| = ρ|12| σ|1| σ|2| “, write the formula for risk (variance) of a portfolio.
σ|p|² =
Σ|i=1| Σ|j=1| w|i| w|j| σ|ij|
= Σ|i=1| Σ|j=1| w|i| w|j| ρ|ij| σ|i| σ|j|
σ|ij|: the Covariance of the two securities.
σ|i|: the variance of security i.
ρ|12|: The correlation coefficient between security 1 and 2.
Week 1 Risk Return -What will the portfolio volatility of a two stock portfolio be?
BA 1.
σ|p|² =
Σ|i=1| Σ|j=1| w|i| w|j| σ|ij|
σ|p|² = w|1|²σ|1|² + w|2|²σ|2|² + 2w|1| w|2| σ|12|
where σ|12| = ρ|12| σ|1| σ|2|
The following equation is therefore equivalent:
σ|p|² = w|1|²σ|1|² + w|2|²σ|2|² + 2w|1| w|2| ρ|12| σ|1| σ|2|
Week 1 Risk Return - Given the two security portfolio variance equation:
σ|p|² = w|1|²σ|1|² + w|2|²σ|2|² + 2w|1| w|2| σ|12|,
What is the interpretation of each part?
w|1|²σ|1|²: Component due variance (idiosyncratic risk) of security 1.
w|2|²σ|2|²: Component due variance (idiosyncratic risk) of security 2.
2w|1| w|2| σ|12|: Component due to the covariance between security 1 and security 2 (systematic risk).
Each security contributes w|1| w|2| σ|12| worth of systematic risk.
Week 2 Risk Return - Consider a portfolio of securities with expected return r|p| = 20% and standard deviation σ|p| = 50%. Suppose the composition of the portfolio is changed, such that the standard deviation reduces. What is this an example of?
Diversification.
Week 2 Risk Return - What iii diversification with a portfolio?
To get at least the same return with lower risk, or lower risk and a lower return.
It is not diversification if the expected return falls though and the risk remains the same.
We need the expected return to stay the same (or improve) AND the portfolio risk to fall (So the standard deviation to fall.
Week 2 Risk Return - Given the portfolio risk equation for two stocks:
σ|p|² = w|1|²σ|1|² + w|2|²σ|2|² + 2w|1| w|2| σ|12|,
What additions would be made if there were three stocks.
We would add
w|3|²σ|3|² + 2w|1| w|3| σ|23| + 2w|2| w|3| σ|23|
So the idiosyncratic risk associated with the additional stock and the systematic risk due to the covariance with the third stock with the other two stocks.
Week 2 Risk Return - If you have calculated the portfolio variance of two stocks and want to calculate the standard deviation when adding a further stock, what would the process be?
You could start from scratch and calculate using the equation, or, given the knowledge of the first portfolio variance, use this to get the standard deviation and use the equation counting the portfolio as a solitary security.
Week 2 Risk Return - When N securities are uncorrelated, what is the portfolio S.D?
σ|p| = [w|1|²σ|1|² + w|2|²σ|2|² + … + w|N|²σ|N|²]^1/2
SO the second part of the equation is removed (the systematic risk) leaving only the stock specific idiosyncratic risk.
Week 2 Risk Return - How do we get to the risk pooling result in which variance is equal to 0 when N approaches infinity and what other axioms are required?
We assume stocks are uncorrelated (strong and unrealistic assumption) so
σ|p| = [w|1|²σ|1|² + w|2|²σ|2|² + … + w|N|²σ|N|²]^1/2
We then assume each share has the same variance and weighting, so w|I| become 1/N
The whole equation simplifies to:
(N * 1/N² σ²) ^1/2 =
(1/N σ²) ^1/2
As N approaches infinity, σ|p| approaches 0 (as this is what we were using the equation to find).
As more and more uncorrelated risks are pooled together, total risk is reduced.
Week 2 Risk Return - Market Risk?
Graph?
The risk that cannot be eliminated through optimal diversifying the investment portfolio.
It is the risk driven by the economy as a whole.
See BA 2 for graph.
Week 2 Risk Return - Total Risk?
Total Risk = Diversifiable risk + market risk.
It is the contribution of an individual security to the risk of a portfolio.
Diversifiable risk contributed to unique risk and can be eliminated through diversification.
Only market risk contributes towards risk of a well diversified portfolio.
Week 2 Risk Return - What does risk pooling show?
That there is one type of risk that cannot be diversified away from, being market risk,
Week 2 Risk Return - Beta (β)?
A measure of sensitivity of the stock, being how much the stock fluctuates given a change in the market (Purely Theoretical)
The market is made up of all stocks, so has a β=1 (this is an assumption)
Securities that move in the same direction but tend to amplify the movement of the market have β > 1.
Those that move in the same direction as the market but tend to reduce the movement have 0 < β < 1.
They will move up or down with the market.
Stocks that move opposite the market are very rare.
Week 2 Risk Return - Beta (β)?
The systematic risk part.
The covariance of the asset with the market portfolio return divided by the variance of the market portfolio
A measure of sensitivity of the stock, being how much the stock fluctuates given a change in the market (Purely Theoretical)
The market is made up of all stocks, so has a β=1 (this is an assumption)
Securities that move in the same direction but tend to amplify the movement of the market have β > 1.
Those that move in the same direction as the market but tend to reduce the movement have 0 < β < 1.
They will move up or down with the market.
Stocks that move opposite the market are very rare.
Week 2 Risk Return - How do we calculate β?
r|i| = α + β|i| r|m| + error|i|
r|m| : Return of market portfolio.
r|i| : Return on security
We use linear regression to calculate the slope of the line.
β|i| = σ|im| / σ|m|²
The beta is the covariance between stock and the market scaled by the variance of the market.