21st Century Investments manages a portfolio, Z, that has zero correlation with the market index and examines the prospects for AMI Enterprises, a manufacturer of laptop batteries. 21st Century Investments derives the following market forecasts:
- Expected return on portfolio Z - 8%
- Expected return on the market index - 14%
- Risk-free rate - 5%
- AMI beta - 1.50
Using the zero-beta form of the capital asset pricing model (CAPM), the equilibrium expected return for AMI is closest to:
The zero beta form of the CAPM replaces the risk-free rate with the return on a zero beta portfolio. Portfolio Z has zero correlation with the market portfolio. Therefore, the beta for portfolio Z also equals zero. Recall the formula for beta:
where covim is the covariance between any asset i and the market index m, σi is the standard deviation of returns for asset i, σm is the standard deviation of returns for the market index, and ρim is the correlation between asset i and the market index. Therefore, the beta will equal zero if the correlation equals zero. The equation for the zero-beta CAPM is:
E(R) = E(Rz) + β[E(Rm) – E(Rz)] = 0.08 + 1.50[0.14 – 0.08] = 0.17 = 17%
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