Renaissance Technologies LLC has named Nathaniel Simons, son of founder James Simons, as co-chair of the pioneering East Setauket hedge fund, according to government filings.
Nathaniel Simons, 53, who had been vice chairman at Renaissance, also is a senior managing director of Meritage Group LP, a San Francisco investment firm.
The appointment appears to set up a succession framework at the hedge fund.
James Simons, 81, retired from day-to-day operations in 2010 and retains the title of nonexecutive chairman.
The elder Simons, who worked for the U.S. government as a codebreaker during the Cold War, was chairman of the Stony Brook University mathematics department from 1968 to 1976. After leaving academia, he started Renaissance in 1982 in the hope that mathematical models could help uncover inefficiencies in the stock and commodity markets.
Despite some early failures, the fund became so successful that James Simons' net worth, estimated at $21.6 billion, makes him the richest Long Islander and the 44th wealthiest person in the world, according to Forbes.
Bloomberg calculated that Renaissance's flagship Medallion Fund, open to the Simons family and Renaissance employees, had posted average annual gains of 39% after fees over the past 32 years.
Nathaniel Simons was named Renaissance co-chairman in November, according to the filing.
Peter Brown continues as chief executive, a title he shared until 2017. That's when James Simons asked co-CEO Robert Mercer to step down after a torrent of controversy related to Mercer's financial support for conservative website Breitbart News and political consultancy Cambridge Analytica.
Renaissance Technologies and the Internal Revenue Service have been locked in a dispute over taxes that some estimates put at $6.8 billion. The IRS maintains that Renaissance from 1999 to 2014 used a stock options technique to make short-term gains appear as more tax-friendly long-term trades.
In recent years, James Simons has turned his attention to scientific projects designed to answer questions about the origin of the universe.
The Simons Foundation pledged $80 million to build and operate an observatory in the Andes mountains of Chile in the hope of detecting gravitational waves thought to be generated immediately after the universe came into being.