Bloomberg the Company & Products

Bloomberg Anywhere Login


Connecting decision makers to a dynamic network of information, people and ideas, Bloomberg quickly and accurately delivers business and financial information, news and insight around the world.


Financial Products

Enterprise Products


Customer Support

  • Americas

    +1 212 318 2000

  • Europe, Middle East, & Africa

    +44 20 7330 7500

  • Asia Pacific

    +65 6212 1000


Industry Products

Media Services

Follow Us

Ex-Citadel Worker Pleads Guilty to HFT Data Theft

Don't Miss Out —
Follow us on:

Aug. 7 (Bloomberg) -- A former Citadel LLC employee pleaded guilty to stealing data from the Chicago investment firm and high-frequency trading computer code from another company.

Yihao Ben Pu, 26, who was first charged in 2011, today admitted taking the proprietary information from Citadel that year and to an earlier theft of trade secrets from an unnamed company based in Red Bank, New Jersey, that developed HFT infrastructure software.

With the plea before U.S. District Judge Charles Norgle, Pu avoided a trial scheduled for Sept. 2. He faces as long as 10 years in prison and a fine of as much as $250,000 on each of the two counts. His sentencing is scheduled for Nov. 7.

U.S. prosecutors are cracking down on intellectual property theft from financial firms, with Manhattan District Attorney Cyrus Vance Jr.’s office having charged at least four analysts or programmers in connection with theft of code. Disputes that used to be resolved in contract litigation are now being criminalized.

Led by founder Kenneth C. Griffin, Citadel manages $20 billion in assets. The firm in 2009 won a court order temporarily blocking former executive Mikhail Malyshev, who led its high frequency trading unit, from starting his own firm, Teza Technologies LLC, claiming he would be violating a non-competition agreement that paid him $30,000 per month.

Flash Boys

Former Goldman Sachs Group Inc. programmer Sergey Aleynikov, who inspired author Michael Lewis’ book “Flash Boys” was accused in 2010 of wrongfully uploading proprietary computer code from that firm before he was supposed to start working at Teza. He was suspended and fired by Teza. After his federal conviction was thrown out, Aleynikov was charged under state law by Vance’s office.

Pu worked for Citadel as a Quantitative Financial Engineer, from May 2010 to Aug. 2011, according to the plea agreement.

“His primary job responsibilities included working with analysts and researchers to develop and enhance certain of Citadel’s HFT strategies,” and he had signed a non-disclosure agreement, according to the filing.

Before joining Citadel, Pu worked for the unnamed New Jersey company for eight months, testing and analyzing its HFT strategies.

Bit Confused

After Assistant U.S. Attorney Patrick Otlewski recited allegations contained in the plea agreement, Norgle asked Pu what he intended to do, leaving the momentarily confused defendant to ask the judge to clarify his question.

Norgle asked if Pu intended to plead guilty. The 2009 Cornell University graduate replied, “Yes, I plead guilty.”

Norgle asked Pu if he knew what he was doing, to which the defendant replied, “Yes,” telling the judge he wasn’t coerced into entering the agreement.

Pu was charged in a 2013 revised indictment with 20 criminal counts, including trade secret theft, wire fraud, unauthorized computer access and the destruction of records. He pleaded not guilty to those charges in April 2013.

Sahil Uppal, a former Citadel HFT strategy researcher and Pu’s co-defendant, still faces charges in the criminal case.

Pu’s lawyers declined to comment after today’s hearing.

Mike Geller, a spokesman for Citadel, said he couldn’t immediately comment on today’s plea. He is affiliated with the firm Edelman Public Relations Worldwide.

The case is U.S. v. Pu, 11-cr-00699, U.S. District Court, Northern District of Illinois (Chicago).

To contact the reporter on this story: Andrew Harris in federal court in Chicago at

To contact the editors responsible for this story: Michael Hytha at Joe Schneider

Please upgrade your Browser

Your browser is out-of-date. Please download one of these excellent browsers:

Chrome, Firefox, Safari, Opera or Internet Explorer.