of a stock is how much it reacts to movements in the market portfolio.

一只股票风险指标β系数直接反应出，The，β,市场组合变动与投资收益的相关性。

耶鲁公开课 - 金融市场课程节选

It will be about the securities market line, about the beta, about the mutual fund theorem, and it will also be about institutions that we have--about investment companies and their management.

证券市场的风险线,beta系数,共同基金定律,还有当下的一些金融机构,包括投资公司,以及他们的管理

耶鲁公开课 - 金融市场课程节选