The IPO, to take place Thursday, will return GM to the New York Stock Exchange for the first time since June of last year, when it was booted off as it headed into bankruptcy protection.
The sale will draw the U.S. government closer to its goal of recouping the $50 billion it gave GM to help it avoid financial ruin.
Demand for GM shares is so strong that the company's bankers are likely to exercise options to sell a maximum number of shares. That means 550 million common shares would be sold by the government and other GM owners starting Thursday for a total value of $18.2 billion.
The government will sell 412 million shares and get $13.6 billion. It will still have about 500 million shares, or about 33 percent of GM. It would have to sell them for $53 a share, or $26.4 billion, for taxpayers to get back their $50 billion back.
At $18.2 billion, the common share sale would be the fifth-largest IPO in history. GM will also sell up to 100 million shares of preferred stock worth a total of $5 billion. The preferred and common shares combined would make the IPO worth $23.2 billion, which could be the largest IPO in history.