An individual, either acting alone or on behalf of someone else, who attempts to devalue a stock by spreading false or exaggerated claims against a public company. After the stock's price has dropped, the basher, or the basher's employer, will then purchase the stock at a lower price than what he or she believes it is intrinsically worth.
This is an illegal activity that can carry significant legal repercussions. The basher is generally paid on the basis of how many lies and negative rumors are spread, which can dramatically affect a stock's value. If an investor believes some of the lies, he or she may sell off the stock at the higher price before it falls. The basher will then purchase the stock and ride out the gains.