So, even if the cost is small, $10 a dose, it quickly amounts to a large amount of money.

因此,即使单只成本很小,可能只有十美元,但是这很快就会累积成为很大的金额

耶鲁公开课 - 生物医学工程探索课程节选

So, the optimal thing to do if you live in a world like this n is to get n as large possible and you can reduce the standard deviation of the portfolio very much and there's no cost in terms of expected return.

如果现实中也这样简单的话,那么你就尽量增大,这样就能让投资组合的标准差,就会大大降低,从预期收益率的角度来看,这样做的成本是零。

耶鲁公开课 - 金融市场课程节选