Coalition members also wrote to the heads of the New York Stock Exchange and the federal Securities and Exchange Commission.

CENTERFORSECURITYPOLICY: Center for Security Policy | Pittsburgh Tribune-Review scorches State��s public pension system over portfolio��s global bad actors��

The explosion of trading in private company stock has drawn the attention of the Securities and Exchange Commission, which has already warned SecondMarket and SharePost, two platforms for trading in private stock, that they are being watched.

FORBES: JP Morgan Starting 'Social Media Fund' To Invest In Twitter, Facebook, And Other Private Companies

Cheney, who raised concerns that his financial stake in Halliburton may pose a conflict of interest if he wins the election, had exercised Halliburton stock options, according to a Securities and Exchange Commission filing.

CNN: Cheney sold $35 million in Halliburton stock in August