Bear raid
A bear raid is a type of stock market strategy, where a trader (or group of traders) attempts to force down the price of a stock to cover a short position. This can be done by spreading negative rumors about the target firm, which puts downward pressure on the share price. This may be a form of securities fraud. Alternatively, traders could take on large short positions themselves, with the large volume of selling causing the price to fall, making the strategy self perpetuating.