THE decade-long probe into the giant hedge fund SAC Capital for insider trading culminated not in a court but, perhaps appropriately, in a press conference. On November 4th Preet Bharara, a federal prosecutor, announced that SAC would plead guilty to five counts of fraud, cease managing money for clients and pay a record fine of $1.8 billion - in Mr Bharara's words, a "just and appropriate price for pervasive and unprecedented institutional misconduct." Yet if SAC was as rotten as he implies, it is puzzling that he has not charged the man who presided over it, Steve Cohen, with any wrongdoing. Returns at SAC were so extraordinary that it could get away with taking as much as half of them in fees, plus 3% of sums invested. SAC proved to be particularly adept at "event-driven" investing, making well-timed bets on key events, such as earnings and innovations. Confessions by six people affiliated with the firm suggest that at least some of the time the insights had untoward roots. Two other employees have been charged with similar conduct. All told, the government claims that SAC traded on inside information about at least 20 companies between 1999 and 2010. SAC's structure may have helped insulate Mr Cohen from unsavoury goings-on. The core operation was linked to four affiliates. These performed their own research and picked stocks, with Mr Cohen allocating capital and receiving "high-conviction" ideas for use in his own portfolio. Meanwhile, SAC was parsimonious in its record-keeping, deleting instant messages every 36 hours and most e-mails every month. There was talk during the investigation that Mr Cohen might be accused of "conscious disregard," a legal concept used to implicate suspects who seem to have gone out of their way to avoid knowledge of a crime. Mr Bharara insists that further charges may yet be brought against SAC personnel. But if the Justice Department had a strong case, says Bradley Bondi, a lawyer with Cadwalader, Wickersham & Taft, it would already have embarked on it. Instead, the Securities and Exchange Commission, a financial regulator, has brought civil charges against Mr Cohen for his alleged "failure to supervise," which could result in further fines. Meanwhile, Mr Cohen can continue to invest his personal fortune, put at $9.4 billion by Forbes. If that estimate is correct, his returns this year alone could cover SAC's settlement.