Date Time Three useful things to know about stock market manipulation As the SEC investigates social media posts for GameStop manipulation, UNSW Business School’s Mark Humphery-Jenner says it is important to remember that market manipulation is illegal. Famed GameStop investor ‘Roaring Kitty’ was recently hit with a securities-fraud lawsuit for his role in GameStop’s surge. The litigation alleges (amongst other things) that he manipulated the stock price and that he misrepresented himself as an amateur investor when in reality he was a licensed broker. The meteoric rise of stocks such as GameStop has raised awareness of financial markets, with the likes of late-night hosts talk about people trading to “spank the Wall Street big boys”, presumably by forcing stock prices to move in a specific way. But, this risks encouraging behaviour that is straight illegal through market manipulation.