A person who is familiar with the matter told Bloomberg that six high-frequency trading firms are to be subpoenaed by New York Attorney General Eric Schneiderman. Schneiderman is reportedly seeking information on the firms' trading strategies, as well as their special arrangements with exchanges and dark pools. The person, who refused to be identified as the details of the investigation have yet to be made public, said that among the firms Schneiderman's office have sent subpoenas to are Chopper Trading LLC, Jump Trading LLC and Tower Research Capital LLC.

Bloomberg contacted Chicago-based Jump Trading chief operating officer Matt Schrecengost and managing director Mark Gorton of New York-based Tower Research for comment, but have yet to received a response from both. There was reportedly no official at Chicago-based Chopper Trading who was immediately available to be asked for comment about the probe.

Last month, Schneiderman expressed his concerns on certain trading platforms who allegedly sell services like faster data feeds. These services reportedly give high-speed trading firms an unfair advantage as they seek to profit from split-second price movements.

Bloomberg said he is not the only one who is concerned about the practice. authorities in the US, including the US Federal Bureau of Investigation are already investigating whether the firms engaged in high-speed trading acted on confidential information in order to gain advantage over their rivals.

According to its website, Chopper was founded in 2002 by Raj Fernando and initially started on fixed-income trading, according to its website. Chopper claimed that it trades on every major asset class. On the other hand, Bill DiSomma and Paul Gurinas founded Jump. Its website said that the company has developed the best trading strategies that allows them to gain foresight on trades using the latest technologies. Gorton, who runs Tower Research, also created the LimeWire music-sharing service. The service had also run into legal trouble in 2011, when it agreed to settle the lawsuit filed by Warner Music Group Corp, Sony Corp and other music label owners over copyright infringement claims for $105 million.