Tesla CEO Elon Musk has previously voiced disapproval of ISS and Glass Lewis, the two proxy advisory firms that are the focus of President Donald Trump's executive order. Samuel Corum/Getty Images

President Donald Trump on Thursday ordered a review of two major proxy advisory firms — companies that advise shareholders on votes — that had previously drawn the ire of Tesla CEO Elon Musk and others in Corporate America.

The executive order singles out the two biggest players in the market: Institutional Shareholder Services (ISS) and Glass Lewis.

Proxy advisory firms like ISS and Glass Lewis provide recommendations on how major investors like pension funds should vote on corporate decisions and at shareholder meetings — sometimes to the consternation of other shareholders or even corpora

See Full Page