SpaceX's 912-Million-Share Unlock Tests a Market Already Awash in Supply

On Thursday, August 6, the largest single lockup expiration since the 2021 IPO boom arrives — and it lands in a market already absorbing an unusual wave of secondary issuance. SpaceX (NASDAQ: SPCX), which raised $86.2 billion in its June IPO at $135 per share, will see 911.5 million insider shares become eligible for sale, representing just under 7% of shares outstanding.^[1] That is the first tranche of a staggered unlock schedule that, by year-end, could release more than $500 billion of stock into the market.^[1]

The timing is uneasy. SpaceX delivered its first quarterly earnings on August 4, beating on revenue — $7.81 billion versus $6.93 billion expected — and narrowing its per-share loss to $0.09 from the $0.26 analysts anticipated.^[2] Adjusted EBITDA came in at $3.5 billion, up 191% year-over-year.^[2] Yet the stock dropped roughly 7–8% in extended trading, not on the revenue line but on capital expenditure: AI infrastructure spending came in above estimates, underscoring the enormous capital requirements analysts have flagged.^[3] Morgan Stanley projects SpaceX will need to raise $670 billion of debt over the next eight years and won’t reach cashflow positivity until 2035; Goldman Sachs is somewhat less bearish, modeling $270 billion in debt and a 2031 cashflow-positive date.^[1] The company’s own prospectus amendment added that it “may issue a significant amount of equity,” meaning the lockup wave could eventually be compounded by primary issuance.^[1]

The Staggered Unlock: What Becomes Eligible and When

The August 6 release is only the opening salvo. Here is the full unlock schedule based on the IPO prospectus terms:

The August 6 tranche could have been larger. Under a performance clause in the prospectus, an additional 455.8 million shares would have unlocked if SpaceX had traded 30% above its $135 IPO price in five of the ten preceding trading sessions. With the stock plunging to a new intraday low of $107.01 on August 4 — roughly 50% below its June 16 peak — that threshold is no longer reachable.^[1]

The key question is not how many shares are eligible but how many are actually sold. Some investors point out that pre-IPO shareholders have had years of tender offers and private secondary transactions to monetize positions. “Those that really needed to monetise rotated out through tenders and secondary sales,” said Vick Seth, CEO of Shaires and a SpaceX investor.^[1] But venture capital firms including Founders Fund, Andreessen Horowitz, and Sequoia Capital hold significant positions, and VCs face pressure to return capital after years of below-average distributions.^[1] My estimate: 60% probability that net selling pressure from the first tranche alone keeps SPCX trading below $115 through the end of August, with a 40% chance that long-term institutional demand absorbs the supply and the stock stabilizes above its post-earnings low.

A Secondary Offering Wave Runs in Parallel

While SpaceX commands the headlines, the underwritten offering calendar this week shows supply arriving from multiple directions:

• Prologis (NYSE: PLD) priced 15 million shares of common stock on August 4, generating approximately $2.1 billion in gross proceeds.^[4] Underwriters J.P. Morgan and BofA Securities have a 30-day option for up to 2.25 million additional shares.^[4] Prologis stated the proceeds would be used for general corporate purposes, including funding a potential combination with SEGRO plc.^[4] The offering closed August 5.

• Twist Bioscience (NASDAQ: TWST) upsized its public offering to $300 million, pricing 3,125,000 shares at $96.00 per share.^[5] The deal was led by Goldman Sachs, William Blair, Leerink Partners, and Guggenheim Securities.^[5] The offering reflects continued investor appetite for synthetic-biology and AI-driven drug-discovery platforms.

• REGENXBIO (NASDAQ: RGNX) announced a $100 million underwritten offering in mid-July, adding to the biotech secondary pipeline.^[6]

The combined supply from these deals — roughly $2.5 billion in a single week — is modest relative to total US equity market volume, but it signals that issuers see a window. When companies raise capital in size, it is typically because they believe demand can absorb it. The fact that both Prologis and Twist upsized their deals suggests book-building went better than initially expected.

The Biotech IPO Window: Open for a Third Straight Week

Attovia Therapeutics (Nasdaq: ATTO) priced its upsized IPO on August 4, selling 17 million shares at $17 per share — the top of its marketed range — and raising $289 million.^[7] The San Carlos, California-based clinical-stage biopharmaceutical company, backed by Goldman Sachs, is developing next-generation biotherapeutics for immune-mediated diseases using its ATTOBODY nanobody platform.^[7] The deal was originally filed for 12.5 million shares at a $15–$17 range before being upsized.^[7]

This marks three consecutive weeks of biotech IPOs — the first such streak since winter 2025.^[8] Through H1 2026, 15 biotech IPOs priced, up 114% from seven in H1 2025 and the highest first-half total since 2021.^[8] Notably, Parabilis Medicines raised $670 million in its June Nasdaq listing, setting a record for the largest biotech IPO of the year.^[8] The pipeline is growing: BlossomHill and Latigo have also filed for offerings in recent weeks.^[8]

The window, however, is selective. Biotech investors are far more discriminating than during the pandemic-era boom, and many companies are pursuing a dual-track process — preparing for an IPO while simultaneously engaging with potential acquirers.^[8] Big Pharma, facing major patent expirations later this decade, is under pressure to acquire rather than build, which provides a floor for biotech valuations even if the public-market route proves uneven.^[8]

The Buyback Counterweight

On the demand side, several companies announced or advanced repurchase programs on August 5:

^[9] Rambus’s accelerated repurchase is notable because it signals confidence from a semiconductor IP company at a time when AI-related names have faced selling pressure. CMC’s $600 million authorization increase, bringing its total repurchase capacity to approximately $717 million, represents one of the larger industrial-sector buyback expansions this quarter.^[9] Internationally, BBVA’s completion of a €4 billion buyback and HSBC’s new repurchase round underscore that European financial institutions continue to return capital at scale.^[9]

The net picture: issuance and repurchase are both elevated. When both sides of the ledger are active, it typically signals a market in transition — companies are rebalancing capital structures rather than uniformly signaling confidence or distress.

SEC Proposes Rescinding Key Regulation NMS Rules

Layered beneath the supply story, the SEC proposed a significant market-structure change in June 2026. The Commission voted to propose rescission of Rules 611 and 610(e) of Regulation NMS — the trade-through prohibition and the restrictions on locked and crossed markets, respectively.^[10] Rule 611, adopted in 2005, requires trading centers to execute orders at the best displayed price across all venues, preventing “trade-throughs” where an inferior price is filled while a better quote exists elsewhere.^[10] Rule 610(e) restricts the display of quotes that would lock or cross the market — situations where the best bid equals or exceeds the best ask across venues.^[10]

The SEC’s stated rationale is that after two decades, Rule 611’s unintended consequences may have hindered rather than helped market quality.^[10] The proposal is open for public comment, and any eventual rule change would reshape how orders interact across the 16 US equity exchanges and dozens of ATS venues. For a market facing a supply wave like SpaceX’s, the plumbing matters: if order-handling rules change, the capacity of the system to absorb large sell-side flows without dislocation could shift materially.

This is a proposed rule, not a final one — the comment period and potential litigation could extend the timeline into 2027. But the direction of travel is clear: the SEC is reconsidering the core architecture of order protection that has governed US equity trading since 2005.

What to Watch Next

1. SpaceX lockup Day 1 (August 6): Watch SPCX volume relative to its 30-day average. If first-day turnover exceeds 50 million shares without a meaningful price decline, it suggests absorption capacity is stronger than the bear case. A drop below $100 would signal that selling pressure is overwhelming demand.

2. The next unlock tranche (70 days post-IPO): The 328.4 million shares releasing at the 70-day mark will test whether the initial tranche was the high-water mark for supply or merely the first wave. That lands in mid-October.

3. Prologis/SEGRO deal progression: Prologis explicitly flagged that the $2.1 billion raise could fund a SEGRO combination.^[4] Watch for regulatory filings and SEGRO shareholder responses — a cross-border logistics REIT merger would be one of the largest real estate combinations in recent years.

4. Biotech IPO cadence: If a fourth consecutive week of biotech pricing materializes, it would signal that the window is structurally open rather than a summer anomaly. BlossomHill and Latigo filings are the ones to monitor.^[8]

5. Reg NMS comment letters: The quality and volume of comment letters on the SEC’s proposed rescission will indicate whether the industry supports the change or plans to push back. Watch for submissions from the major exchanges and SIFMA.

The base case here is not a supply-driven market break. It is a market absorbing a historically large but staggered unlock while simultaneously welcoming new issuance and buyback activity. The 60/40 lean is toward orderly absorption — but the 40% tail is real, and it centers on SpaceX-specific dynamics: if AI sentiment deteriorates further and venture funds accelerate distributions, the staggered unlock schedule could produce a rolling pressure pattern that lasts through November’s post-Q3 earnings release of 1.3 billion additional shares. That is the scenario worth hedging against.