SpaceX (SPCX), valued at a reported $1.8 trillion, is positioned to become the largest IPO in history by a significant margin.
The business itself is genuinely exceptional, with Starlink generating profits, launch economics that no competitor can match, and a deep defense contract pipeline.
Despite those strengths, the stock is widely expected to price at a substantial speculative premium, which is precisely the environment where lockup period mechanics matter most to investors.
A lockup period is a legally binding restriction, typically 90 to 180 days, that prevents founders, executives, and early investors from selling their shares after a company goes public.
When lockup periods expire on high-momentum stocks, two forces collide simultaneously: a surge in available supply and a large pool of early holders sitting on significant unrealized gains.
Palantir remains the clearest historical example, with insiders including Peter Thiel selling tens of millions of shares after retail enthusiasm drove the stock from $10 to near $40, causing a 13% single-session decline.
Rivian (NASDAQ: RIVN) dropped roughly 20% in a single day after Ford (NYSE: F) disclosed it would sell its full stake at the 180-day lockup mark.
Uber (NYSE: UBER) hit an all-time low on its own expiration date, sitting 40% below its IPO price, while even Snowflake’s staggered schedule still produced an 11% drop over its final expiration week.
Rather than using a single expiration date, SpaceX has designed a rolling schedule that releases shares to the market in measured stages over the first 180 days.
Two days after its first earnings report, insiders can sell up to 20% of their holdings, with another 10% unlocking early if the stock holds 30% above its IPO price for five of ten consecutive trading days.
Following that, 7% tranches free up at regular intervals through the first 135 days, with a further 28% releasing after the third-quarter earnings report and the remainder at the standard 180-day point.
Elon Musk and select major backers sit outside this schedule entirely, having committed to a full 366-day lockup, a meaningful positive signal given Musk’s majority voting control.
The initial float is deliberately tight at roughly $75 billion worth of shares, representing under 5% of SpaceX’s total implied value.
A Nasdaq fast-entry rule makes SpaceX eligible for Nasdaq-100 inclusion just 15 days after listing, which would force index funds tracking that benchmark to purchase SpaceX shares at scale.
The rolling lockup structure is designed so that new shares enter circulation gradually enough to meet that index-driven buying demand rather than overwhelming it all at once.
Early venture capital investors who have waited more than a decade for liquidity have every incentive to sell into a strong price, and the schedule makes clear when they will do so.
The key dates for investors to watch are the index-inclusion window around early July, the first earnings report likely in August, and the third-quarter report expected around late October or November.
Each of those dates represents a moment where supply and demand get tested in real time, with material volumes of newly unlocked shares entering a market priced at close to 100 times trailing revenues.
A slower release schedule eases the pressure that crushed Palantir, Rivian, and Uber investors at their respective lockup expirations, but it does not resolve the fundamental question of whether the entry price is simply too high.
At close to 100 times revenue, SpaceX is asking investors to back an AI and space infrastructure thesis priced for perfection, with very little room for any unexpected setback.
