What does the Equity Beta (Be) represent in the cost of equity calculation?

Equity Beta (Be) is a measure that indicates how sensitive a firm's stock returns are to fluctuations in the overall market returns. It reflects the level of systematic risk associated with holding a company's equity compared to the risk of the market as a whole. A beta greater than one suggests that the firm’s stock is more volatile than the market, indicating higher risk, while a beta less than one indicates lower volatility and risk. This characteristic makes beta a critical input when calculating the cost of equity using models like the Capital Asset Pricing Model (CAPM), where it serves to assess the risk premium that investors require for taking on the risk associated with the company's equity relative to a risk-free rate and the overall market.

Understanding the sensitivity of the firm's stock returns helps investors make informed decisions regarding their investment portfolio, particularly when evaluating the trade-off between risk and return.