Unless you’ve been to the moon, you know that Elon Musk’s SpaceX just shot down the moon Biggest IPO of all time and raised about $86 billion in its public stock offering last month.
The reusable rocket maker did this while selling only a tiny fraction – between 4% and 5% – of its shares. The other 95% – made up of about 12.5 billion shares – are kept behind bars under one of the most Byzantine and complicated lock-up schemes in history.
To set the level, lock-up periods are standard after an IPO; Founders, top executives and early venture capitalists typically agree not to sell their shares for 180 days. The point, as IPO advisor Lise Buyer of Class V Group explains, is twofold. First, it forces the people who know the company best to sit through at least one earnings report so they can’t dump their shares to the public right before a bad quarter. Second, it sends a reassuring signal at what could otherwise be a volatile and difficult time in the life of a new public company.
“It’s a message to the new buyers that the people who know the company best still believe in it and will stick with it,” Buyer said.
But when the lock-up period expires, usually right after 180 days, there is typically an oversupply of shares entering the market, putting downward pressure on the stock price. Over the last decade, underwriters have pushed busy technology companies to adopt staggered or shorter release dates on which insiders could sell their shares, some even tying them to earnings or share price increases to dampen the inflow. Airbnb, DoorDashReddit and Snowflake have either shortened or staggered the 180 days.
However, SpaceX took the flexible lockup approach, wrapping it in a puzzle, strapping it to a puzzle, and sending it to a colony on Mars.
There are 15 dates for sales in public marketsas shown in the company’s documents. Anyone who isn’t a Musk or big investor can sell their shares during the 180-day window, as they will be unlocked in 7% shares on various dates in August, September and October and then two trading days after SpaceX’s second-quarter 2026 results, which will be its first venture as a publicly traded company. After the next earnings report, there will be another large tranche, and then whatever is left can be sold after 180 days. There are also dates tied to other earnings releases and stock price increases.
Avery Marquez, who tracks IPOs and lock-up structures as director of investment strategy at Renaissance Capital, described how much of an outlier this is: “This is one of the most, if not the most, complicated lock-ups we’ve ever seen.”
The buyer said she had never seen such a large percentage of a company’s shares unlock before 180 days.
“This is outside the bounds of anything we’ve seen before,” she said. “I expect their transfer agent will drink tequila because it will be a bit difficult to cope with,” she joked.
Why create such a complicated lockdown plan? Buyer and Marquez said it was aimed at preventing the billions of stocks behind bars from flooding the market all at once.
Doing so “could have disastrous consequences for the stock price if everyone wanted to sell,” Marquez said.
Hans Tung, managing partner at Notable Capital and an early SpaceX investor through a company acquired by the rocket maker, said the timeline reads as an attempt to give shareholders peace of mind rather than see everything sold off at once. Some will hold on to the stock “because that’s how it performs over a long period of time,” while others who got in in the last five to 10 years will likely sell to show some liquidity, he said.
“I think this series of moves is designed for most shareholders to sell something every time,” said Tung, whose fund has a small stake in SpaceX and a much larger position in Anthropic, which also provides computing power for SpaceX.
Tung said he had no inside information, but noted that because of their size, Anthropic and OpenAI could potentially take on similar locks to SpaceX if they go public.
“The amount of money involved is just very large. So some people are going to have to make exits along the way,” he said. This is designed to be done in multiple tranches rather than a principle where everyone competes against each other with a six-month lock-in period and after that everyone can just do whatever they want.”
There is another reason why investors might want to hold on to the stock instead of selling it immediately, Tung added. The listing marks the beginning of a new phase for SpaceX. And Musk’s xAI, which is part of SpaceX, is likely to acquire some companies.
He pointed to Cursor, the AI coding startup with which SpaceX struck a compute deal before its IPO. Days after the listing, SpaceX exercised an option to purchase Cursor for $60 billion in SpaceX shares.
Now that SpaceX is public, Musk has liquid currency to fund more deals like this, Tung said – and “the more companies it acquires, the more value the stock will have, so.” [investors] will last longer.”
SpaceX has achieved stunning growth in its short time on the public market. The stock, which was priced at $135 when it went public, opened at $150 on its first day of trading and rose to $226 per share in the following days. While the company has since given back some of those gains, the stock now trades at around $162, giving SpaceX a market cap of $2.61 trillion.
And then there’s Musk
There’s a wild card in the mix. Musk holds around 6.4 billion shares, representing about 82% of the voting power in SpaceX, between his voting 10-shares-in-one Class A shares and Class B shares. Musk cannot sell for 366 days, and there are no early release provisions at all. But then everything is unlocked at once in one fell swoop.
Musk’s unusual lock-up structure presents investors with extremes and gives the stock a ballast of stability in the first year, followed by the possibility of a supernova event. Although it is almost inconceivable that Musk would decide to sell all of his shares at this point given the negative signal associated and the resulting impact on the company, the risk factor cannot be ignored.
Musk’s track record with his Tesla The stock can give an indication of what to expect. Musk has retained his stake in the electric car maker and taken out loans to avoid the capital gains tax implications he would face. He only sold Tesla shares as a last resort.
Jay Ritter, an IPO expert and professor at the University of Florida, said he wouldn’t be surprised if Musk didn’t sell SpaceX shares at all.
“He doesn’t have to worry about where his next meal is coming from, and if he does, it will probably be a tiny fraction of the, what, 6 billion shares he owns,” Ritter said.
Musk could even buy more from SpaceX, Marquez speculated.
“It’s possible we’ll see him buying stocks as they’re released. People start selling them and he buys them up,” she said. “With Elon Musk, anything is possible.”
Tung doesn’t expect Musk to jump in immediately, but wouldn’t rule out later buybacks.
“I don’t think he’ll buy right away, but I think he’ll buy quite a bit over the next five to 10 years [stock] Back when he felt like it was the right thing to do,” he said. “He is who he is and he’s been doing this for a long time.” I see no reason why he should behave any differently.”
Buyer also said the same thing, also refusing to speculate about Musk’s plans.
“He has no use for the money and I’m sure he believes the stock is undervalued,” she said. “Maybe he won’t sell a single share.”
Whether Musk’s investors can do the same remains to be seen.