Ann: Successful launch of US Trading, page-14

I see it the other way, shorters want to borrow high now so they can sell as they expect the price to drop, not rise, as that is the only way they make money. They then buy back at the lower price to return the shares back to you.

So they borrow BHP from you today and sell it at $42 and pay you a percentage fee based on that $42, let's say $1. So for them BHP needs to drop at least $1 just to break even. When they close the short they buy the stock back and return it to you, so they make more money the bigger the price drops from when they borrowed the shares from you. If the price goes up a shorter loses money (short squeeze).