“I had been working practically every moment I was not in school,” he wrote in a story for the company.
The company created in the 19th century by his great-grandfather Maurice embarked on numismatics on an ancillary basis, buying and selling collector’s coins and currencies in addition to its primary foreign exchange function. It then diversified into the trade of antiques and rare stamps.
In 1935, after converting the business into a rare coin dealership, Morton and Joseph Stack held their first public auction. In 1953, Stack’s moved to a gallery on 57th Street in Midtown Manhattan. (It is now on Park Avenue at East 58th Street and has galleries in other cities.)
In 2011, Stack’s merged with Bowers & Merena to create Stack’s Bowers Galleries.
Mr. Stack served as President of the Professional Numismatists Guild for two years from 1989. In 1993 he received the Founder’s Award, the guild’s highest honour.
In addition to his son, he is survived by his wife, Harriet (Spellman) Stack; his daughter, Suzanne; two grandchildren; and five great-grandchildren. He lived on Long Island.
The Stack Gallery was considered an inviting global club by many coin dealers and collectors. But Mr. Stack hasn’t been shy about promoting the company’s financial success.
“There are people who sell gold and silver bars, rolls and bags of coins, who call themselves coin dealers, and some of them are probably making over 100 million dollars a year,” he told The New York Times in 1984. “When you say ‘rare coin dealers’ and talk about companies that sell both directly and at auction, we’re the biggest dealer in parts in the United States.
He distinguished numismatists, whom he assiduously courted, and investors.
“If a collector and an investor were to abandon a sinking ship, the collector would take with him the rarest and most aesthetically pleasing pieces, regardless of their market value,” he told The Times in 1977. “The investor would try to take as many of their coins as possible, starting with the most valuable ones.