Beta (β): Definition and Use in CAPM

Beta measures a stock's sensitivity to market movements. It is a key input to Capital Asset Pricing Model (CAPM) when estimating the cost of equity.

CAPM Formula:

Use a long-term market return premium and an appropriate risk-free rate for your jurisdiction. Beta can be estimated from regression or using provider-supplied levered/unlevered betas.

Notes

  • Beta > 1.0 indicates higher volatility than the market
  • Beta < 1.0 indicates lower volatility than the market
  • Unlevered beta removes the effect of financial leverage
  • Historical beta may not predict future sensitivity

Why This Matters:

Beta is crucial for determining the required return on equity investments. It helps investors understand the risk-return tradeoff and is essential for calculating WACC in valuation models.

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