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What Is Betting Against Beta And How Bab Linked From Capm? Essay

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What is betting against beta and how BAB linked to CAPM? 1.1 Link BAB factor to CAPM One assumption of CPAM model is that all investors invest in the same portfolio with the highest expected excess return per unit of risk and combine leverage using risky-free assets to maximize their utility. However, there are some investors constrained in such kind of leverage due to margin requirements or any prohibitions. For these investors, they tend to overprice the risky high-beta assets instead of leverage. Therefore, the risky assets with higher betas require lower risk-adjusted returns than lower-beta assets with leverage because the tilting behavior alleviates the no-leverage constraint (Black, Jensen and Scholes 1972). Here the BAB strategy generates a funding constrained CAPM model which is based on the standard CAPM model but provides a more practical implement to investors’ portfolio construction. 1.2 Market-neutral betting against beta factor (BAB factor) Under the above circumstance, arbitragers (investors with unlimited leverage) could imply betting against beta factor by short selling a higher-beta portfolio, leveraged to a beta of 1, and purchasing a lower beta portfolio, de-leveraged to a beta of 1. There are several propositions stated in BAB strategy. The equilibrium required return for security s is: E_t (〖r^s〗_(t+1) )=r^f+ψ_t+〖β^s〗_t λ_t , where ψ is the agents’ average Lagrange multiplier, measuring the tightness of funding constraints, and λ is the risk

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