A historically large post-IPO lockup expiration is imminent, with markets assessing its potential impact on the share price.

According to the SpaceX prospectus, a maximum of approximately 911.5 million shares held by insiders will be released from trading restrictions on August 6, representing a market value of around $116 billion. This date comes just two days after the company's first quarterly earnings report. By year-end, the total number of shares available for trading is set to surge from the current roughly 639 million to 5.33 billion.

Facing this massive supply overhang, SpaceX's stock is under significant pressure. Since its closing high on June 16, the share price has fallen 37%, erasing over $425 billion in market capitalization. As of Tuesday's trading session, the stock was up 3.8%, potentially ending a seven-day losing streak.

Data from S3 Partners indicates that approximately 30% of the current free float is sold short, with short sellers sitting on paper profits of around $7 billion.

A unique aspect of this lockup expiry is that SpaceX did not follow the standard 180-day post-IPO lockup period. Instead, it designed a phased release schedule, aiming to expand the float while attempting to avoid a severe shock to market supply and demand.

Phased Unlocking: An Uncommon Structure

Compared to traditional IPO lockup expirations, SpaceX's mechanism of staggered, multi-phase releases is rare in the market. The prospectus shows that the over 900 million shares unlocking on August 6 are only the first batch. The scale of the unlock will continue to expand in subsequent months, with the total market free float jumping to 5.33 billion shares by early December, an increase of over seven times from the current level.

Notably, a conditional trigger mechanism exists after August 6. If SpaceX's stock price reaches $175.50 on at least five out of the ten trading days preceding an earnings announcement, an additional maximum of 455.8 million shares will be eligible for trading immediately after that earnings release.

Based on Monday's closing price of $119.85, reaching that threshold would require a further gain of over 46%, which the market widely views as a difficult hurdle.

Elon Musk holds approximately 7.8 billion shares, representing about 60% of the total shares. The prospectus indicates that the lockup period for his holdings extends to more than one year after the company's June listing, meaning they will not contribute to the selling pressure in the short term.

Early Investors Face Lucrative Exit Opportunities

Despite the recent significant pullback in the share price, early shareholders still hold substantial paper gains compared to pre-IPO valuation levels. SpaceX was valued at approximately $400 billion in a private financing round a year ago.

Earlier this year, SpaceX completed the acquisition of xAI. At the time, that transaction implied an overall valuation for SpaceX as high as $1 trillion, with xAI valued at $250 billion, according to reports. This deal allowed many investors to realize billions of dollars, with their equity stakes in the public company now worth multiples of their initial investment.

The phased unlocking arrangement means that early private market investors and insiders will have successive exit windows over the coming months and can choose to sell their holdings in batches at different price points.

Short Sellers Pile In, IPO Market Sentiment Dampened

Expectations of the lockup expiry, combined with valuation debates, have attracted significant short-selling activity. Data from S3 Partners shows about 30% of the current free float is sold short, with short sellers holding paper profits of approximately $7 billion.

Over the past 12 trading sessions, SpaceX's stock has closed lower on 10 days. Triggering factors include not only the lockup expiry expectations but also the Starship rocket launch abort due to engine issues and a broader market rotation away from artificial intelligence-themed stocks.

The extreme volatility in SpaceX has had a spillover effect on the broader market for new listings.

According to data, the weighted average return for companies that went public this year has fallen to negative 4.4%. Even excluding SpaceX and SK Hynix, the overall return for this year's new listings is only 5.3%, significantly underperforming the S&P 500's 9.4% gain over the same period.

Striking a balance between increasing liquidity and stabilizing the share price will be the core challenge for SpaceX and its underwriting team in the months ahead.