In general, less volatile stocks have done better over time than more volatile stocks, which is somewhat inconsistent with the notion of efficient markets.

一般来说，波动小的股票在长期内比波动大的股票,表现要好，一定程度上,这和金融市场有效论的观点是相悖的。

耶鲁公开课 - 金融市场课程节选

We'll come back to this, but beta of the stock is a measure of how much it moves with the market and the alpha of a stock is how much it outperforms the market.

回到原先的话题,beta用以衡量,本公司跟随市场变化的程度,alpha衡量超过市场的表现

耶鲁公开课 - 金融市场课程节选