Formulas Flashcards
Name this formula and use:
V=D1/ (r−g)
Constant Growth Dividend Discount Model (DDM):
- Calculates the value of a dividend-paying security (with constant dividend growth) in dollar terms.
What are the determinants of stock purchase decision using the Constant Growth Dividend Discount model formula
When IV (intrinsic value) < MV (market value) the stock is overvalued and Er (expected return) < k; (required return) the investor should avoid the stock
When IV > MV, the stock is undervalued and Er > k; the investor should buy the stock
When IV = MV, the stock is fairly valued and Er = k; the investor should buy the stock
Name this formula and use
r =D1/P + g
Expected Rate of Return
The rate an investor should expect based on the price paid for a security.
Where:
D1= next year’s dividend
P = market price paid for a security
g = the dividend growth rate
What are the determinants of stock purchase decision using the expected rate of return model formula
When Er>k, the stock is undervalued and IV > MV; the investor should buy the stock
When Er
Name this formula and use
COVij=ρijσiσj
Covariance
Measures how one security behaves as a direct result of another.
Where:
ρij = correlation between securities i and j
σi = standard deviation of security i
σj = standard deviation of security j
How is covariance applied to investment decision making
Since Covariance helps us understand the directional relationship between investments, a positive covariance would indicate that two investments would tend to move in the same direction. A negative covariance would indicate that two investments would tend to move inversely.
Covariance, however, doesn’t tend to allow the investor to understand the severity of that co-movement.
Name this formula and use
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σp=√W2i σ21+W2jσ2j+2WiWjCOVij
Standard Deviation of a Two Asset Portfolio
Provides the weighted standard deviation for a two-stock portfolio. It helps understand how much an outcome can vary from the expected outcome. With investing standard deviation is used to understand how much an investment’s return can vary from the expected return.
Where:
Wi = weight of stock ‘i’
Wj = weight of stock ‘j’
σi = standard deviation of stock ‘i’
σj = standard deviation of stock ‘j’
COVij = covariance between ‘i’ and ‘j’
Name this formula and use
βi= COVim / σ2m = (Pim)(σi) / σm
Beta
Provides risk as a measure of volatility relative to that of the market. Therefore, an investment with a beta of around 1.0 will have a similar performance to the market in a given time period. An investment with a beta of less than 1.0 will be less volatile than the market. This means when the market is down, the investment will be down less. Conversely, if the market is up, the market is up less.
With a beta greater than 1.0, the investment will be more volatile than the market. This means when the market is up, the investment will be up more. When the market is down, the investment will be down more.
Where:
σi = standard deviation of the individual security
ρim= correlation between an individual security and the market
COVim= covariance between an individual security and the market
σm = standard deviation of the market
Name this formula and use
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σr√ ∑t=1n(rt−r⎯⎯)2 / n
Standard Deviation of a Population
Identifies the deviation of a single security over a series of periods of return.
Where:
σr = standard deviation of results from the expected return
Σ = summation of all terms
n = number of periods being considered
rt = actual return
r⎯⎯ = average return
Name this formula and use
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Sr √ ∑t=1n(rt−r-)2 / (n−1)
Standard Deviation of a Sample
Identifies the deviation of a single security over a series of periods of return.
Where:
Sr = standard deviation of results from the expected return
Σ = summation of all terms
n = number of periods being considered
rt = actual return
r⎯⎯ = average return
Calculate using: ∑+ = each period return; g, x (zero key) = mean); g, s (decimal key) = standard deviation
How do you apply standard deviation of sample results
Investors can use average (or expected) return and standard deviation to give them an idea of how variable a stock’s performance can be. The greater the standard deviation, the less predictable a stock’s performance will be in a given time period.
Name this formula and use
ri = rf+(rm−rf)βi
Capital Asset Pricing Model (CAPM)
Used to determine a theoretically appropriate required rate of return of an asset. CAPM helps an investor quantify what return they should expect from an investment, or how much return should the investor require from the investment given an expected market return and the risk of the investment relative to that market (Beta).
ri = the investor’s required rate of return
rf = risk-free rate (T-Bill rate serves this end)
rm = return of the market (S&P 500 or some broad index)
βi = beta of the security being measured for the required return
Market risk premium is the same as (rm−rf);
Name this formula and use
αp=rp−[rf+(rm−rf)βp]
Jensen’s Performance Index (Alpha)
Measures the performance of a portfolio manager relative to the performance of the market. The purpose of alpha is to quantify the risk-adjusted performance of an investment manager relative to the risk they exposed the portfolio to in terms of beta
One of the functions of the capital asset pricing model (CAPM) is to draw the security market line (SML). The SML plots out all of the expected returns of portfolios relative to their Betas (a measure of market risk) given a market return and a risk-free rate of return.
αp = difference of return from the amount required by investors
rp = return of the portfolio
rf = risk-free rate of return
rm = return of the market
βp = Beta of the portfolio being measured
(calculation following rp- = CAPM)
How do you interpret alpha results relative to stock portfolio performance
If alpha is positive, the portfolio manager provided a greater amount of return than what was expected given the amount of risk the portfolio was exposed to in terms of beta.
If alpha is negative, the portfolio manager provided less return than what was expected given the amount of risk the portfolio was exposed to in terms of beta.
If alpha is zero, the portfolio manager provided the exact amount of return that was expected given the amount of risk the portfolio was exposed to in terms of beta. This would plot right on that security market line (SML).
Name this formula and use
Tp=(rp−rf) / βp
Treynor Ratio
Measures the risk-adjusted performance of a portfolio manager, when R2 is substantially high enough (R2 > .7). Otherwise if the R2 is not substantially high enough (R2 < .7), use the Sharpe Ratio.
Treynor Ratio is useful as a comparative value, meaning that you need to compare the Treynor Ratios of two or more investments to get use out of it.
When interpreting the results of a Treynor Ratio comparison, you always want to choose the investment with the higher Treynor Ratio as it will provide a greater risk-adjusted rate of return.
Tp = Treynor Index equals:
rp = return of the portfolio
rf = risk free rate of return
βp = beta of the portfolio being measured