Pump and dump

"Pump and dump" (P&D) is a form of microcap stock fraud that involves artificially inflating the price of an owned stock through false and misleading positive statements, in order to sell the cheaply purchased stock at a higher price. Once the operators of the scheme "dump" sell their overvalued shares, the price falls and investors lose their money. Stocks that are the subject of pump and dump schemes are sometimes called "chop stocks".