Prediction market traders expect SpaceX to close its first day of trading with a market capitalisation above $2 trillion, a feat achieved by only five other US companies in history: Nvidia, Apple, Alphabet, Microsoft and Amazon.
Polymarket's "SpaceX IPO closing market cap" contracts, which have attracted more than $10 million in trading volume, assign a 69% probability to the company finishing today's session above the $2 trillion mark.
Based on the initial market capitalisation of $1.77 trillion set by last night's $135 per share pricing, a $2 trillion close would equate to a rally of roughly 13% on debut.
The odds shorten dramatically below that level. Traders price an 84% chance of a close above $1.8 trillion, a near 2% gain on the IPO valuation, while the probability of finishing above $1 trillion sits at 99%, effectively pricing out any scenario of a catastrophic first session.
Above $2 trillion, conviction fades quickly. A close above $2.2 trillion, which would require a gain of around 24%, is priced at 40%, while the more exotic strikes attract little support: $2.5 trillion carries odds of 8%, $3 trillion just 3%, and a close above $4 trillion, which would briefly make SpaceX a rival to Apple and Alphabet for second place in global rankings, is given a 1% chance.
The distribution tells a clear story: traders expect a strong but not euphoric debut, with the bulk of probability massed in a band between roughly flat and up 25%.
Other venues are slightly more aggressive. Pre-IPO perpetual futures on Hyperliquid, the crypto derivatives exchange, indicate SpaceX could jump more than 20% in its first session, which would put the closing valuation in the region of $2.1 trillion to $2.2 trillion.
The mechanics support the bullish lean. The offering was oversubscribed roughly 3.5 to 4 times, with more than $250 billion of demand chasing $75 billion of stock, and the free float of around 4% to 5% of the company leaves unsatisfied institutional demand competing for scarce shares in the open market. MSCI fast-track index inclusion begins tomorrow, adding mechanical buying within days.
The Polymarket contracts resolve on the official closing price of the first trading day, with market capitalisation defined as total outstanding shares multiplied by the closing share price on the primary exchange's official listing page.
For the AI flotations queued behind SpaceX, the resolution of these markets matters beyond bragging rights. A close above $2 trillion would tell Anthropic and OpenAI, both of which filed confidentially this month, that public markets will pay a premium to private marks. A close below $1.8 trillion would suggest the opposite.
