Pump & dump
wiki : "Pump and dump" 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" 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".
