The different stocks tend to move up and down together.

不同的股票会同时涨跌。

耶鲁公开课 - 金融市场课程节选

If you look at the ten best-performing Internet funds from 1997 to 2002, the time-weighted return is 1.5% per year positive, so the funds went way up and then they went way down.

这十个表现最好的网络投资基金,从1997年到2002年,时间加权回报率是每年1.5%,基金一路涨涨跌跌

耶鲁公开课 - 金融市场课程节选