二百五十天啤打值

Beta is the sensitivity of a stock's returns to the returns on some market index (e.g., S&P 500). It can also be defined as the risk of the stock to a diversified portfolio. Therefore the beta of a stock will be much lower than its (the stock's) standard deviation.

The Beta coefficient, or financial elasticity (sensitivity of the asset returns to market returns, relative volatility), is a key parameter in the Capital asset pricing model (CAPM).

The β coefficient measures the asset's non-diversifiable risk, also called systematic risk or market risk, measures the rate of return of the market and measures the rate of return of the asset. On an individual asset level, measuring beta can give clues to volatility and liquidity in the marketplace.

As a general guidance to Mary, Beta values can be briefly characterized as follows:
·β less than 0: Negative Beta is possible but not likely. People thought gold stocks should have negative Betas but that hasn't been true.
·β equal to 0: Cash under your mattress, assuming no inflation!
·β between 0 and 1: Low-volatility investments (e.g., utility stocks).
·β equal to 1: Matching the index.
·β greater than 1: Anything more volatile than the index.
·β Much Greater than 1 Impossible, because the stock would be expected to go to zero on any market decline.

To sum up, beta is a good indicator of how risky a stock is. The more risky a stock is, the more its Beta moves upward. A low-Beta stock will protect you in a general downturn.