Providence, R.I. is suing dozens of Wall Street banks and other financial companies over high-frequency trading.
The suit says stock exchanges, investment banks and others defrauded investors by manipulating market data in favor of split-second stock-trading firms.
The suit's defendants include the Nasdaq Stock Market and the New York Stock Exchange; major banks such as JPMorgan Chase, Goldman Sachs and Citigroup; and trading firms including Chopper Trading and Jump Trading.
The lawsuit comes amid heightened government scrutiny into whether advantages in computer hardware and placement enable some to get millisecond timing advances on trades.
The federal complaint was filed Friday in New York on behalf of investors who traded stocks in the U.S. since April 18, 2009.