<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. A hedge fund is a type of investment fund that uses a variety of different strategies to make money. One of the most common is short selling. In short selling, a hedge fund borrows a stock, sells it, and then waits for the price to fall. When the price falls, the hedge fund buys the stock at a lower price and returns it to the lender, thus earning a profit.