Robert Mercer

Robert Leroy Mercer (born July 11, 1946) is an American hedge fund manager, computer scientist, and political donor. Mercer was an early artificial intelligence researcher and developer and is the former co-CEO of the hedge fund company Renaissance Technologies.

Mercer played a controversial role in the campaign for the United Kingdom to leave the European Union, led by Dominic Cummings, with £3.9 million being spent on his data analytics and machine learning company AggregateIQ. He has also been a major funder of organizations supporting right-wing political causes in the United States, such as Breitbart News, the now-defunct Cambridge Analytica, and Donald Trump's 2016 campaign for president. He is the principal benefactor of the Make America Number 1 super PAC.

In November 2017, Mercer announced he would step down from Renaissance Technologies and sell his stake in Breitbart News to his daughters. He was the majority owner of SCL Group, a self-described "global elections management agency", before it was dissolved in 2018. In 2021, Mercer was involved in possibly the largest tax settlement in U.S. history, as he, James Simons, and other executives at the hedge fund Renaissance Technologies were ordered to pay as much as $7 billion to the IRS in back taxes.

Mercer grew up in New Mexico. He developed an early interest in computers and in 1964 attended a National Youth Science Camp in West Virginia where he learned to program a donated IBM computer. He went on to get a bachelor's degree in physics and mathematics from the University of New Mexico. While working on his degree, he had a job at the Air Force Weapons Laboratory at Kirtland Air Force Base writing programs where, though he felt he produced good work, he felt it was not optimized. He later said the experience left him with a "jaundiced view" of government-funded research. He earned a Ph.D. in computer science from the University of Illinois at Urbana–Champaign in 1972.

Mercer joined IBM Research in the fall of 1972 and worked at the Thomas J. Watson Research Center in Yorktown, New York, where he helped develop Brown clustering, a statistical machine translation technique, as part of a speech recognition and translation research program led by Frederick Jelinek and Lalit Bahl. He also worked on IBM alignment models. In June 2014, Mercer received the Association for Computational Linguistics Lifetime Achievement Award for this work.

In 1993, Mercer joined hedge fund Renaissance Technologies after being recruited by executive Nick Patterson. The founder of Renaissance, James Harris Simons, a mathematician, preferred to hire mathematicians, computer scientists, and physicists rather than business school students or financial analysts. Mercer and a former colleague from IBM, Peter Brown, became co-CEOs of Renaissance when Simons retired in 2009. Renaissance's main fund, Medallion, earned 39% per year on average from 1989 to 2006.

In 2014, a bipartisan Senate panel estimated that Medallion investors underpaid their taxes by some $6.8 billion over more than a decade, by masking short-term gains as long-term returns. In 2014, Renaissance managed $25 billion in assets. In November 2017, Mercer announced that he would be stepping down from his position at Renaissance Technologies. The decision was taken after the hedge fund faced a backlash over Mercer's political activism.

Mercer appears in the Paradise Papers as a director of eight Bermuda companies, some of which appear to have been used to legally avoid US taxes.