SAC Investors Ask to Withdraw $1.7 Billion Clients of SAC Capital Advisors have asked to withdraw $1.7 billion from the giant hedge fund amid an intensifying insider trading investigation involving the fund, according to people briefed on the matter. That amount represents slightly more than a quarter of the $6 billion that SAC manages for clients, and is the largest amount ever withdrawn from the fund. Clients had to inform SAC by Thursday - a regularly scheduled quarterly redemption deadline - whether they wanted to redeem their money. While the outflows are a blow to the fund founded by Steven A. Cohen, which boasts one of the best investment track records on Wall Street, they are expected to have little impact on the fund's business. More than half of SAC's assets under management, which stood at $15 billion as of mid-January, belong to Mr. Cohen and his employees. "As we have been saying, the redemptions will have no significant impact on our funds," an SAC spokesman said in a statement. Still, the amount highlights the reputational damage wrought on SAC by the wave of insider trading cases involving the Stamford, Conn.-based hedge fund. Among the high-profile clients taking money out of the fund include a Citigroup unit that manages money for wealthy families and Lyxor Asset Management, a division of the French bank Societe Generale. Other SAC clients have taken a more wait-and-see approach, keeping their money with the fund while monitoring developments in the insider trading inquiry. Blackstone Group, SAC's largest outside investor, took this route, saying it would keep its $550 million investment with the fund for at least the next three months while it learns more information about the latest criminal case against SAC. In late November, the government brought charges against Mathew Martoma, a former SAC portfolio manager, in a prosecution that they are calling the most lucrative insider trading scheme ever uncovered. The trades at the center of the case involve Mr. Cohen, who has not been charged and denied wrongdoing. Mr. Martoma has pleaded not guilty. At least seven other current or former SAC employees have been tied to allegations of insider trading while working there, four of whom have pleaded guilty. And the Securities and Exchange Commission has advised SAC that they might file a civil fraud action against the firm related to the Martoma trades.