More than 900 million shares became newly available to buy or sell with Thursday's release, doubling what was available previously. SpaceX shares rose 2.5% to $110.92 in noon trading Thursday. A day earlier they had one of their biggest routs in SpaceX's short history as a public company, dropping nearly 14%. Morgan Stanley was one of the investment banks that earned big fees helping take the SpaceX public last month. In June, Musk sold SpaceX shares to the public for the first time in the biggest initial public offering ever.