An illegal practice whereby two or more market makers collectively attempt to influence and change the price of a stock. Ghosting is used by corrupt companies to affect stock prices so they can profit from the price movement. Taobiz explains Ghosting This practice is illegal because market makers are required by law to act in competition with each other. It is known as "ghosting" because, like a spectral image or a ghost, this collusion among market makers is difficult to detect. In developed markets, the consequences of ghosting can be severe.