In April 2012, hedge fund insiders became aware that the market in credit default swaps was possibly being affected by the activities of Bruno Iksil, a trader for JPMorgan Chase & Co., referred to as "the London whale" in reference to the huge positions he was taking. Heavy opposing bets to his positions are known to have been made by traders, including another branch of J.P. Morgan, who purchased the derivatives offered by J.P. Morgan in such high volume. Early reports were denied and minimized by the firm in an attempt to minimize exposure. Major losses, $2 billion, were reported by the firm in May 2012, in relation to these trades and updated to $4.4 billion on July 13, 2012. The disclosure, which resulted in headlines in the media, did not disclose the exact nature of the trading involved, which remains in progress and as of June 28, 2012, was continuing to produce losses which could total as much as $9 billion under worst-case scenarios. The item traded, possibly related to CDX IG 9, an index based on the default risk of major U.S. corporations, has been described as a "derivative of a derivative". On the company's emergency conference call, JPMorgan Chase Chairman, CEO and President Jamie Dimon said the strategy was "flawed, complex, poorly reviewed, poorly executed, and poorly monitored". The episode is being investigated by the Federal Reserve, the SEC, and the FBI.