Nothing about SpaceX 's IPO is ordinary. The rocket maker is aiming to raise a record sum, by a wide margin, at a historic valuation, and will be controlled by Elon Musk , who's also CEO of Tesla , another trillion-dollar company. When it comes to the mechanics of the share sale, SpaceX is offering a take-it-or-leave-it price of $135, rather than providing a range and then pricing the deal based on demand, as is customary in IPOs. But as the stock offering gets underway on Thursday, certain