The admission of insider trading that Steven Cohen’s SAC Capital made yesterday brings a symbolic end to his two-decade career managing money for outside investors, but SAC’s fate was already sealed in July when the US Department of Justice first laid criminal charges.

At that moment, even Mr Cohen’s staunch supporters felt compelled to pull their funds from the firm, and SAC began preparing for its new future as a slimmed-down organisation that only manages the Cohen family’s money.

That fortune is estimated at between $8bn and $9bn, so the operation will immediately become one of the largest of the US’s estimated 4,000 “single family offices”, which manage purely for rich individuals and their heirs. But SAC’s strategy and the number of people it employs are likely to change substantially.