By Pras Subramanian

SpaceX's (SPCX) record-breaking IPO enters its final stretch, with the deal set to "price" Thursday night ahead of the stock's debut on the Nasdaq (^IXIC) on Friday, June 12. But this pricing night will look nothing like the ones Wall Street and investors are used to.

In a conventional IPO (which technically is the night it "prices" as opposed to the first day of trade, which is its "market debut"), the company and its underwriters look over orders and weigh demand and settle on a final price, often above or below the marketed range.

SpaceX and CEO Elon Musk are going a totally different route, though not altogether surprising given Musk's whims and contrarian nature. SpaceX said in its updated IPO prospectus that it was selling stock at $135, rather than offering a range.

The price was fixed before SpaceX's investor roadshow began last week, making Thursday's pricing a formality. At $135 per share, SpaceX will raise around $75 billion, and have an anticipated market capitalization of $1.78 trillion.

SpaceX plans to sell 555.6 million shares to hit that $75 billion, with underwriters holding a "greenshoe," or option to sell additional shares if demand outstrips the initial allotment, of approximately 83 million shares worth around $11.2 billion. The company reportedly told investors it would stop taking orders Wednesday, a day earlier than usual, giving SpaceX and its bankers all of Thursday to determine who gets shares in the largest IPO ever.

The biggest open question is how much ends up with retail investors. SpaceX is reportedly targeting a retail allocation of roughly 30% — far above the 5% to 10% typical of most IPOs — but the final figure remains unsettled. Individual investors have been able to place orders through Charles Schwab, Fidelity, Robinhood, SoFi, and Morgan Stanley's E-Trade, among other brokerage platforms, though Robinhood moved its deadline up a day to 4 p.m. ET on Wednesday.

In addition, SpaceX's IPO shares are running four times oversubscribed, per Reuters, which indicates strong demand; however, this amount is often inflated by institutional investors to make sure they receive enough stock for their clients. In actuality, demand could be less, adding to the uncertainty.