Well, it can only be true if security selection and market timing detract from institutional returns or individual returns in the aggregate.

唯一的可能性就是证券选择,和市场时机选择,给机构和个人带来的是负的回报

耶鲁公开课 - 金融市场课程节选

Those three tools are asset allocation, market timing, and security selection.

这些工具是,资产配置,市场时机选择和证券选择

耶鲁公开课 - 金融市场课程节选

So, it's not surprising that asset allocation explains more than 100% of returns and that, for the community as a whole, market timing and security selection are costly and lower the community's aggregate investment returns.

因此资产配置能解释100%以上的回报,也不足为奇了,对投资者整体来说,市场时机选择,和证券选择是有代价的,降低了总的投资回报

耶鲁公开课 - 金融市场课程节选