Roberta Smith gives a little history on the Scull collection and its relationship to the modern art market in her review of the Acquavella show:

All told, this exhibition conveys an amazing appetite and instinct for the new, the next new and the next new after that. These impulses propelled Robert Scull, and his wife, Ethel, through one of the greatest, most influential shopping sprees in postwar American art. It came to a screeching halt in the fall of 1973, with an auction at Sotheby Parke Bernet, as Sotheby’s was then called, two blocks north of the Whitney Museum.

That auction, “The Collection of Robert C. Scull,” was the first of contemporary American art by a single seller. Its 50 lots of mostly Pop Art brought in $2.2 million (about $10.8 million in 2010 dollars), just above the high estimate, along with stunning evidence that the value of 1960s art would rise exponentially. It was immediately seen as a fall from grace for the Sculls — nouveaux riches cashing in — and the New York art world too.

It supposedly gave birth to what many think of as the mercenary art market of today. Actually, things were pretty quiet for the rest of the 1970s, and the Sculls had already shocked certain quarters of the art world in 1965 by auctioning more than 20 Abstract Expressionist paintings in order to buy Pop Art. (At the time, Mark Rothko took it as further depressing evidence that his “moment” — barely a decade old — had already passed.)

Appetite for the New and the Next New (New York Times)