Guess who’s back? General Motors stock returned to the NYSE Thursday, opening at $33 per share and then jumping 7 percent in early trading. It has been a year and a half since the company was last on the market. At $33, GM shares are one of the largest initial public offerings in history, and the move is expected to bring in $23.1 billion total. There are 549.7 million common shares and 92 million preferred shares sold at $50 each. The stock sale will halve the Treasury Department’s ownership to 26 percent, and will speed up the White House’s plan to divest itself from the company. GM’s offering was underwritten by Morgan Stanley, JP Morgan Chase, and a number of other banks that agreed to accept a lower-than-average fee for the high-profile project.