In '98, I forget which way, but one of the share classes 20% was at a 20% discount to the other and that persisted for several years, so you have economically identical things trading at different prices.

在98年，我不记得是为什么，一支这种类型的股票,比另一只股票便宜,而且这种现象持续了好几年的时间，因此你拥有经济意义上完全相同,但是却以不同价格进行交易的东西。

耶鲁公开课 - 金融市场课程节选

Also, a single mutual fund may be available in several share classes with different fees.

WSJ: Questions to Ask Your Financial Adviser About Fees

All told, 362 companies, or 6% of those publicly held, list dual share classes.

FORBES: Magazine Article

When the same fund had two share classes, I selected the share class with the lowest fee.

FORBES: Pick Your Muni Funds Carefully