New York's attorney general is the latest to jump into the high-speed trading party, issuing subpoenas to Wall Street firms seeking documents on whether they're getting an unfair leg-up over their less technologically savvy competitors.

The revaluation of the subpoenas from Eric Schneiderman's office, first reported by the Wall Street Journal, brings to at least four the number of agencies probing what the New York Attorney general has described as "Insider Trading 2.0."

Other entities investigating whether Wall Street firms are taking advantage of "differences in delays, or latencies, of trade information distributed between trading venues" include the Commodity Futures Trading Commission, the Securities and Exchange Commission and the Federal Bureau of Investigation.

The Journal said that Chicago-based Jump Trading and Chopper Trading and Tower Research Capital of New York were among those targeted by the latest subpoenas demanding e-mail and other documents.

The companies did not immediately respond for comment.