Steven A. Cohen's hedge fund SAC Capital Advisors told investors on Friday it would no longer cooperate unconditionally with the U.S. government's insider trading investigation.
In a brief letter to investors, the $15 billion hedge fund did not elaborate but said it believes the next few months will be critical in the investigation.
The letter, which an investor in the fund who did not want to be identified read to Reuters over the telephone, also said while SAC believes in transparency, it may not be able to give frequent updates to investors.
The investor in the fund said he was not concerned by SAC's announcement. He added that the fund is up 5.96 percent so far this year.
An SAC spokesman declined to comment.