PM: Risk and Return 2 Flashcards
Combining risk free and risky assets =
The optimal CAL (capital allocation line) =
best CAL is the one that offers the most preferred set of possible portfolios in terms of their risk and return.
different expectations of expected returns, standard deviations and correlation between risky assets will lead to different optimal risky asset portfolios and CALs.
Homogeneous expectations =
a simplifying assumption of modern portfolio theory is HOMOGENEOUS EXPECTATIONS - regarding expected returns, standard deviation and correlations.
as a result, all investors face the same EFFICIENT FRONTIER and have the same OPTIMAL RISKY PORTFOLIO and CAL
Optimal risky portfolio and CAL (given homogeneous expectations) =
optimal CAL is tangent to the efficient frontier.
all investors use the SAME PORTFOLIO OF RISKY ASSETS
but may choose different weights of risk free/risky assets
market portfolio (of risky assets) and the Capital Market Line =
all investors hold the same risky portfolio, the MARKET PORTFOLIO of all risky assets.
the optimal CAL for all investors is the CAPITAL MARKET LINE
along which EXPECTED PORTFOLIO RETURN is a LINEAR function of PORTFOLIO RISK
Capital Market LIne Equation =
y int: Rf, risk free rate
Slope: [E(Rm)-Rf]/SDm
so that if an investor takes no risk, SDp=0, the return is the risk free rate.
We can rearrange to get the below.
The investor will receive one unit of the market risk premium for accepting one unit of market risk, SDm.
Borrowing and Lending portfolios =
Simple assumption that investors can both lend (invest) and borrow at the risk free rate - this means they can be invested at below or above the MARKET PORTFOLIO.
E(Rp) = Wm x E(Rm) + (1-Wm) x Rf
SDp = Wm x SDm
The market portfolio and active vs passive mgmt =
Those who think markets are not informationally efficient, and think their values/prices are more ‘correct’ than the market, will invest actively and not simply invest in the market portfolio.
an active manager will over and under weight securities based on their evaluation of value/price.
Systematic vs unsystematic risk =
the market portfolio contains all risky assets/has reduced all risk that can be reduced through diversification.
this is UNSYSTEMATIC RISK (unique, diversifiable, firm-specific)
this leaves SYSTEMATIC RISK (non diversifiable, market risk)
both portfolios and individual securities can have unsystematic and systematic risk
TOTAL RISK = SYSTEMATIC RISK + UNSYSTEMATIC RISK
Risk vs # of portfolio assets =
Risk decreases at a decreasing rate when more securities are added to the portfolio - at a point the standard deviation will remain constant (12-18, 30, the number depends on the study)
Systematic Risk and the cost of diversification =
Capital market theory says
- equilibrium security returns don’t depend on total risk/SD, they depend on systematic risk
- Diversification is FREE
- thus, investors will not be compensated for unsystematic risk that can be reduced throught FREE DIVERSIFICATION
SYSTEMATIC RISK: is measured by the contribution of a security to risk in a well diversified portfolio
EXPECTED EQUILIBRIUM RETURN FOR A SECURITY WILL DEPEND ON ITS SYSTEMATIC RISK
Return generating and multi factor models =
RETURN GENERATING MODELS are used to estimate expected returns based on spefic factors.
A MULTIFACTOR MODEL uses macroeconomic, fundamental and (less so due to accuracy) statistical factors - with estimates of how sensitive a security is to changes in particular factors.
Multi Factor Model Equation =
expected return above the risk free rate = the sensitivity, or factor loading (Bs), x expected value of the factor for the period.
First factor is often E(Rm-Rf), the expected market return.
Fama and French Model (+Carhart) =
Fama and French multifactor model: firm size, firm book value to market value ratio, return on the market portfolio - risk free rate.
Carhart adds a fourth facto - price momentum using prior period returns.
Single factor/index model =
expected excess return based on on factor exposure to the market return, factor weight/sensitivity “BETA i”