Beta is an important metric for understanding the risk profile of an investment. It helps investors assess how sensitive a stock or portfolio is to market movements, which is crucial for portfolio diversification and risk management. For example, if a stock has a beta of 1. 5, it means that the stock is expected to be 50% more volatile than the market. Investors can use beta to determine how much risk they are taking on in relation to market movements and adjust their portfolio allocation accordingly.