Other portfolio creation techniques Sharpe ratio Tangency portfolio Tangency portfolio Ludˇek Benada Department of Finance, office - 402 e-mail: benada@econ.muni.cz Other portfolio creation techniques Sharpe ratio Tangency portfolio Content 1 Other portfolio creation techniques 2 Sharpe ratio 3 Tangency portfolio Other portfolio creation techniques Sharpe ratio Tangency portfolio Content 1 Other portfolio creation techniques 2 Sharpe ratio 3 Tangency portfolio Other portfolio creation techniques Sharpe ratio Tangency portfolio Portfolio creation considering a risk-free asset Other portfolio creation techniques Sharpe ratio Tangency portfolio Portfolio creation considering a risk-free asset Four possible scenarios for creating a portfolio: Other portfolio creation techniques Sharpe ratio Tangency portfolio Portfolio creation considering a risk-free asset Four possible scenarios for creating a portfolio: Short sell is allowed and there exists a rf Other portfolio creation techniques Sharpe ratio Tangency portfolio Portfolio creation considering a risk-free asset Four possible scenarios for creating a portfolio: Short sell is allowed and there exists a rf Tangency portfolio Other portfolio creation techniques Sharpe ratio Tangency portfolio Portfolio creation considering a risk-free asset Four possible scenarios for creating a portfolio: Short sell is allowed and there exists a rf Tangency portfolio Short sell is allowed, but any rf is not available Other portfolio creation techniques Sharpe ratio Tangency portfolio Portfolio creation considering a risk-free asset Four possible scenarios for creating a portfolio: Short sell is allowed and there exists a rf Tangency portfolio Short sell is allowed, but any rf is not available Mean-variance portfolio Other portfolio creation techniques Sharpe ratio Tangency portfolio Portfolio creation considering a risk-free asset Four possible scenarios for creating a portfolio: Short sell is allowed and there exists a rf Tangency portfolio Short sell is allowed, but any rf is not available Mean-variance portfolio Short sell is banned and there exists a rf Other portfolio creation techniques Sharpe ratio Tangency portfolio Portfolio creation considering a risk-free asset Four possible scenarios for creating a portfolio: Short sell is allowed and there exists a rf Tangency portfolio Short sell is allowed, but any rf is not available Mean-variance portfolio Short sell is banned and there exists a rf Cut-off portfolio Other portfolio creation techniques Sharpe ratio Tangency portfolio Portfolio creation considering a risk-free asset Four possible scenarios for creating a portfolio: Short sell is allowed and there exists a rf Tangency portfolio Short sell is allowed, but any rf is not available Mean-variance portfolio Short sell is banned and there exists a rf Cut-off portfolio Short sell is banned and a rf is not available Other portfolio creation techniques Sharpe ratio Tangency portfolio The shape of efficient frontier by considering a rf Risk-free asset is changing the shape of affordable and efficient portfolios Other portfolio creation techniques Sharpe ratio Tangency portfolio The shape of efficient frontier by considering a rf Risk-free asset is changing the shape of affordable and efficient portfolios The incorporation of rf is consistent with the preferences of a rational investor Other portfolio creation techniques Sharpe ratio Tangency portfolio The shape of efficient frontier by considering a rf Risk-free asset is changing the shape of affordable and efficient portfolios The incorporation of rf is consistent with the preferences of a rational investor Lending vs. borrowing and the efficient frontier . . . Other portfolio creation techniques Sharpe ratio Tangency portfolio Content 1 Other portfolio creation techniques 2 Sharpe ratio 3 Tangency portfolio Other portfolio creation techniques Sharpe ratio Tangency portfolio Sharpe ratio Other portfolio creation techniques Sharpe ratio Tangency portfolio Sharpe ratio Reward to variability ratio: Other portfolio creation techniques Sharpe ratio Tangency portfolio Sharpe ratio Reward to variability ratio: SR = Rp − rf σp Other portfolio creation techniques Sharpe ratio Tangency portfolio Sharpe ratio Reward to variability ratio: SR = Rp − rf σp The relation between SR and efficient frontier . . . Other portfolio creation techniques Sharpe ratio Tangency portfolio Content 1 Other portfolio creation techniques 2 Sharpe ratio 3 Tangency portfolio Other portfolio creation techniques Sharpe ratio Tangency portfolio Tangency portfolio or max. SR portfolio Objective function: SR(w) = wT µ − rf 1 wT w Other portfolio creation techniques Sharpe ratio Tangency portfolio Tangency portfolio or max. SR portfolio Objective function: SR(w) = wT µ − rf 1 wT w Optimization problem: Other portfolio creation techniques Sharpe ratio Tangency portfolio Tangency portfolio or max. SR portfolio Objective function: SR(w) = wT µ − rf 1 wT w Optimization problem: max SR(w) with respect to w Other portfolio creation techniques Sharpe ratio Tangency portfolio Calculation procedure Other portfolio creation techniques Sharpe ratio Tangency portfolio Calculation procedure Structure of the portfolio: Other portfolio creation techniques Sharpe ratio Tangency portfolio Calculation procedure Structure of the portfolio: w = −1 (µ − rf 1) 1T −1 (µ − rf 1) Other portfolio creation techniques Sharpe ratio Tangency portfolio Calculation procedure Structure of the portfolio: w = −1 (µ − rf 1) 1T −1 (µ − rf 1) Portfolio return: Other portfolio creation techniques Sharpe ratio Tangency portfolio Calculation procedure Structure of the portfolio: w = −1 (µ − rf 1) 1T −1 (µ − rf 1) Portfolio return: Rp = rf + (µ − rf 1)T −1 (µ − rf 1) 1T −1 (µ − rf 1) Other portfolio creation techniques Sharpe ratio Tangency portfolio Calculation procedure Structure of the portfolio: w = −1 (µ − rf 1) 1T −1 (µ − rf 1) Portfolio return: Rp = rf + (µ − rf 1)T −1 (µ − rf 1) 1T −1 (µ − rf 1) Portfolio variance: Other portfolio creation techniques Sharpe ratio Tangency portfolio Calculation procedure Structure of the portfolio: w = −1 (µ − rf 1) 1T −1 (µ − rf 1) Portfolio return: Rp = rf + (µ − rf 1)T −1 (µ − rf 1) 1T −1 (µ − rf 1) Portfolio variance: σ2 p = (µ − rf 1)T −1 (µ − rf 1) (1T −1 (µ − rf 1))2 Other portfolio creation techniques Sharpe ratio Tangency portfolio More intuitive calculation approach Other portfolio creation techniques Sharpe ratio Tangency portfolio More intuitive calculation approach Finding the extremum of a function: Other portfolio creation techniques Sharpe ratio Tangency portfolio More intuitive calculation approach Finding the extremum of a function: f (⃗w) = Rp − rf σp → max Other portfolio creation techniques Sharpe ratio Tangency portfolio More intuitive calculation approach Finding the extremum of a function: f (⃗w) = Rp − rf σp → max under weight restriction: n i=1 wi = 1 Other portfolio creation techniques Sharpe ratio Tangency portfolio More intuitive calculation approach Finding the extremum of a function: f (⃗w) = Rp − rf σp → max under weight restriction: n i=1 wi = 1 if we know: Rp − rf = n i=1 wi (ri − rf ) Other portfolio creation techniques Sharpe ratio Tangency portfolio More intuitive calculation approach Finding the extremum of a function: f (⃗w) = Rp − rf σp → max under weight restriction: n i=1 wi = 1 if we know: Rp − rf = n i=1 wi (ri − rf ) σp = n i=1 w2 i ∗ σ2 i + n i=1 n j=1|i̸=j wi ∗ wj ∗ σi,j Other portfolio creation techniques Sharpe ratio Tangency portfolio Getting the weights Let´s assume: λ = Rp − rf σ2 p and further, substitute: Zk = λ ∗ wk then we can write: ri −rf = Z1σi,1+Z2σi,2+Z3σi,3+· · ·+Zi σ2 i +· · ·+Zn−1σi,n−1+Znσi,n and finally: wk = Zk n k=1 Zk