In 2005-08, over a dozen put warrants traded in China went so deep out of the money that they were certain to expire worthless. Nonetheless, these warrants attracted a speculative frenzy: for each warrant, billions of Yuan traded with an average daily turnover rate close to 300%, and at substantially inflated prices. The publicly observable underlying stock prices make the zero warrant fundamentals common knowledge to all market participants. This warrants bubble thus presents a unique opportunity to study bubble mechanisms, so far only available in laboratory environments. We find evidence supporting the resale option theory of bubbles: investors overpay for a warrant hoping to resell it at an even higher price to a greater fool.