Measuring Risk and Return Flashcards
One-period Arithmetic rate of return
Rt = (Pt - Pt-1)/Pt-1
or with dividends
Rt = (Pt + Dt - Pt-1)/Pt-1
Percentage change
One-period Geometric (continuously compounded) rate of return
Rt = ln(Pt/Pt-1)
or with dividends
Rt = ln(Pt+Dt/Pt-1)
Explain the geometric (continuously compounded) rate of return
The rate of return needed to increase wealth by a certain amount if returns are constantly paid in infinitely small parts and constantly reinvested
N-period return using one-period geometric return
Geometric return = Rg1 + Rg2 +…+ RgN
N-period return using one-period arithmetic return
Arithmetic return = [(1+R1)(1+R2)…(1+Rn)] - 1
Converting continuously compounded returns into arithmetic returns
R arith = e^(Rcont) - 1
Converting arithmetic returns into continuously compounded returns
R cont = ln (1+R arith)
Holding period yield
The yield an investor would obtain for holding the asset over a certain period of time
= (Income + Vt - Vt-1) / Vt-1
= Income / Vt-1 + (Vt-Vt-1) / Vt-1
= Income Return + Capital Gains Return
Arithmetic Expected Return
= (R1 + R2 + … + Rn) / n
Variance of a single asset (=(St dev)^2)
= [(X1 - Xbar)^2 + (X2 - Xbar)^2 + … + (Xn - Xbar)^2] / n
Z transformation
z = (x-xbar)/st dev
Correlation
= ρ = Cov(X,Y)/σxσy
Covariance
= [(X1-Xbar)(Y1-Ybar)+…+(Xn-Xbar)(Yn-Ybar)]/n
Expected Portfolio Return
= w1ER1 + w2ER2 + … + wnERn
Portfolio Variance (for two assets only)
= w1^2Var(R1) + w2^2Var(R2) + 2w1w2*Cov(1,2)