Four of eight people charged in a penny stock “pump and dump” scheme that defrauded $290 million from thousands of investors were arraigned on Thursday following a two-year investigation.

Anthony Thompson, 38, of Bethesda, Maryland, Jay Fung, 40, of Delray Beach, Florida, Hanna Schmieder, 39, of Los Angeles and Kenneth Oxsalida, 59, of Sebring, Florida, all pleaded not guilty before Judge Roger Hayes in in state Supreme Court in Manhattan.