<human>:  Why did the hedge fund manager Bill Ackman short Herbalife?
<bot>: Bill Ackman is a well-known hedge fund manager. He’s famous for shorting Herbalife. Ackman thinks that Herbalife is a pyramid scheme, and he thinks that the company is not really making money, and that it’s just a big scam. He thinks that Herbalife is going to collapse. Ackman’s prediction has not come true yet, but I think he will be proven right eventually.