Robert Mnuchin, a prominent figure who made his mark as a pioneer of block trading during a 33-year career at Goldman Sachs & Co. and later transitioned into a respected art dealer, has died at the age of 92. His son, Steven Mnuchin, notably served as the US Treasury secretary during the first term of President Donald Trump. Mnuchin passed away on Friday at his home in Bridgewater, Connecticut, as reported by the New York Times.

Alongside Gus Levy, who was a senior partner from 1969 to 1976, Robert Mnuchin was instrumental in making Goldman Sachs an innovator in moving substantial blocks of securities. This often involved hundreds of thousands of shares in a single company, executed through a single transaction that meticulously matched buyers and sellers without disrupting the broader market. When necessary, the firm utilized its own account as a bridge to facilitate these large trades. This revolutionary practice, known as block trading, became an essential tool for serving the burgeoning needs of large institutional clients – including pension funds, insurance companies, and mutual funds – which began to dominate financial markets in the 1960s.

Mnuchin conveyed to the Wall Street Journal in 1971 that handling such significant stock positions required both courage and substantial capital, qualities few firms possessed. His leadership was further highlighted in 1971 when the New York Stock Exchange instituted a rule mandating negotiated commissions on trades exceeding $500,000; Mnuchin executed the very first such transaction. By 1978, the Journal had acknowledged him as the “dean of block traders,” and his hands-on management style earned him the nickname “Coach.”

A defining moment in Goldman Sachs’s block trading history was “Operation Eagle,” a massive transaction that began with a phone call to Mnuchin in January 1976. The head of New York City’s pension fund sought the firm's assistance in selling a $500 million portfolio of common stocks and simultaneously acquiring a new lineup of stocks indexed to the overall market. As detailed by Charles D. Ellis in his 2008 book, The Partnership: The Making of Goldman Sachs, the firm had to bid a single price to buy the entire portfolio and then create the exact new portfolio specified by the city, acting as an ‘at risk’ principal rather than merely an agent. Secrecy was paramount to prevent competitors from trading ahead of Goldman’s moves, which would have increased costs. The five-week effort involved selling small blocks of holdings daily, with the firm active intermittently for each particular stock. By mid-March, New York City’s pension fund announced that Goldman Sachs had secretly completed this monumental $1 billion purchase and sale, with the final cost to the pension system being an incredibly low $2.9 million, or less than one-third of 1%.

Robert Elliot Mnuchin was born on September 5, 1933, in New York, to Leon Mnuchin, an attorney, and Harriet Gevirtz. The family moved to Scarsdale, New York, during his elementary school years. He earned a bachelor’s degree from Yale University in 1955 and served in the Army before joining Goldman Sachs in 1957 as a trainee in the equity department. In 1957, he married Elaine Terner, with whom he had two sons, Steven and Alan, both of whom later entered finance and worked at Goldman Sachs. This marriage ended in divorce, and in 1964, he married Adriana Abelow, with whom he had two daughters, Lisa and Valerie. While Robert Mnuchin was a lifelong Democrat, contributing to candidates like Hillary Clinton, his son Steven’s role as US Treasury secretary under President Trump presented an unlikely political pairing.

At Goldman, Mnuchin rose to the position of general partner and in 1976 became co-head of trading and arbitrage. By 1980, he was named to the management committee. He retired from Goldman in 1990, just nine years before the firm, Goldman Sachs Group Inc., went public in 1999. Soon after retiring, he and his wife, Adriana, purchased the Mayflower Inn in Washington, Connecticut, a luxury hotel and spa which they renovated with 19th-century antiques before selling it in 2007.

Following his distinguished career on Wall Street, Mnuchin turned his passion for art collecting into a new profession. He opened L&M Arts, a gallery on New York’s Upper East Side, with his partner Dominique Levy, a former director of international sales at Christie’s. The gallery showcased works by post-World War II masters such as Willem de Kooning, Jackson Pollock, and Frank Stella. Mnuchin articulated a key difference between his two careers, stating that on Wall Street, they simply provided liquidity for clients without advising them on what to buy or sell, whereas in the gallery, he curated and advised. Artspace magazine lauded his gallery in 2015 for presenting