Definition: pump 'n' dump
A semantic attack involving fraudulent information that depresses or raises stock values. The perpetrators benefit by buying or selling shares while prices are distorted. One example was a fake press release in April 1994, claiming that a company called PairGain was being unexpectedly bought out at USD $19 per share. PairGain shares rose from $8.50 to $11.25 before the scam was discovered. The hacker was arrested for stock fraud.