SpaceX Lockup Test: 911 Million Shares Unlock as IPO Pipeline Surges and Reg NMS Faces Rescission

Today is the day the IPO market has been bracing for. Approximately 911.5 million SpaceX (SPCX) shares — worth roughly $116 billion based on recent prices — become eligible for sale as the company’s first lockup period expires^[1]. The unlock could more than double the public float of a stock that debuted just eight weeks ago at $135, and under a price-based early-release provision, it could triple it^[2].

This is not a standard 180-day lockup. SpaceX’s underwriting banks engineered a staggered release schedule spanning nearly a year, with additional tranches freeing up to 12.9 billion more shares by mid-2027^[2]. CEO Elon Musk’s roughly 42% stake remains locked until June 2027, and executive officers are generally restricted until after fourth-quarter results. But employees and early investors — many sitting on gains at multiples of pre-IPO cost basis — face their first window to sell^[2].

The stock has been under pressure well before the unlock. SPCX closed at $114.92 on August 6, up 6.1% on the day^[3], but still down roughly 49% from the June 16 intraday record of $225.64^[1]. Shares fell 7% in after-hours trading on August 4 following SpaceX’s first earnings report, which showed a stronger-than-expected 92% revenue increase but also higher-than-anticipated AI capital expenditure^[2]. The company told investors it is on track for annualized revenue of $100 billion by year-end^[2].

Who Sells — and What It Signals

The critical variable is not how many shares unlock but how many actually hit the bid. Renaissance Capital senior strategist Matt Kennedy noted that employees and early investors are “sitting on such massive gains that they’ll have a very strong incentive to realize a return and diversify”^[2]. R.F. Lafferty & Co. CEO Robert Hackel, whose firm fields calls from pre-IPO investors, described this as “the most talked-about lockup in the history of IPO lockups,” with some sellers looking to rotate proceeds into private positions in Anthropic, OpenAI, or Anduril Industries^[2].

On the other side, Falcon Wealth Planning founder Gabriel Shahin reported that contacts among SpaceX insiders show no eagerness to sell: “They’re long-term believers in SpaceX”^[2]. Options markets are already pricing extreme volatility — Shahin called options premiums “sheer insanity,” making hedging prohibitively expensive for holders seeking downside protection^[2].

Projecting the range of outcomes: if even 10-15% of unlocked shares are sold in the coming weeks, that represents roughly $12-17 billion of supply hitting a stock with a still-thin float. A 30% selldown — not implausible given the magnitude of embedded gains — would approach $35 billion. The mitigating factor is that many recipients are individuals rather than institutions, and individual selling tends to be more staggered than the block-dump pattern that a fund liquidation would produce. Base rates from large-lockup expiries suggest the heaviest pressure concentrates in the first two to four weeks, then tapers as the new float finds its equilibrium.

Biotech IPOs: The Other Story This Week

While SpaceX dominates the headlines, the IPO calendar this week tells a quieter but equally significant story. Braveheart Bio (BRVE) priced an upsized offering of 21.2 million shares at $18 — above its $15-$17 range — raising $382.5 million^[4]. The cardiovascular-focused biopharmaceutical company opened at $30.20 on its first trade, a 68% surge, and traded near $30.68 with a market cap of approximately $2.17 billion^[5]. The deal was more than 10x oversubscribed^[5].

Braveheart became the 22nd biotech to go public this year, with five debuts in the last two months alone^[4]. Attovia Therapeutics (ATTO), a clinical-stage company developing treatments for immune-mediated diseases, also priced its upsized IPO this week after filing on August 4^[6]. U.S. biotech and pharmaceutical IPOs have produced a weighted average return of 55% through late July, according to Bloomberg data cited by IPOScoop^[6].

The broader July market context is more mixed. Eight IPOs raised a combined $29.3 billion, but that figure was driven almost entirely by SK hynix (SKHY), which raised $26.5 billion in the largest U.S. equity offering from a foreign issuer in history^[7]. The SK hynix ADR rose 12.8% on its Nasdaq debut^[8]. Excluding that mega-deal, July issuance was well below the historical monthly average of 20 IPOs^[7]. The Renaissance IPO Index sank 14% in July, underperforming a flat S&P 500^[7].

The Supply-Demand Math

Goldman Sachs Research tracks roughly 50 U.S. IPOs year to date — about double the same period last year and the most since 2021 — with combined dollar issuance of approximately $120 billion, essentially tied with 2021’s record pace^[9]. The firm’s IPO Barometer, which blends rates, CEO confidence, and valuations, reads 140 against a long-term average of 100 — not at 2021’s euphoria levels, but at the top of the range^[9].

The question investors keep asking is whether this supply will overwhelm the market. Goldman’s Ben Snider offers three reasons it probably will not — at least not this year. First, deal count, while up, is tracking near the 25-year average of roughly 100 per year, a far cry from 2021’s 250-plus or 1999’s nearly 400^[9]. Second, combined IPOs and follow-ons are forecast at about $700 billion this year, which scales to roughly 1% of total equity market capitalization — actually below the long-term average^[9]. Third, corporate buybacks are projected to exceed $1 trillion, meaning corporate demand for shares will outweigh corporate supply^[9].

The math gets harder in 2027. Many of this year’s IPOs came public with small floats — SpaceX sold only about 4.3% of its shares in the offering^[10]. As lockups expire and additional tranches release, the supply overhang grows. Goldman projects that the supply-demand balance tips toward a more challenging outlook next year and beyond^[9].

The Market-Structure Backdrop: Reg NMS Rescission

The supply story is unfolding against the most significant proposed change to U.S. equity market structure in two decades. On June 11, 2026, the SEC proposed rescinding Rule 611 of Regulation NMS — the trade-through prohibition — and Rule 610(e), which bars locked and crossed quotations^[11].

Rule 611, adopted in 2005, requires trading centers to prevent executions at prices inferior to protected quotations displayed elsewhere. The SEC’s rationale for rescission rests on three arguments: market forces can now shape execution quality without the rule; Rule 611 has produced unintended consequences including exchange proliferation, complex order types, and institutional costs; and the rule is no longer necessary given today’s automated, highly interconnected markets^[11].

The implications are substantial. Trading centers and wholesalers would gain flexibility to design routing and execution strategies without being required to access every better-priced protected quote. Smaller exchanges that benefit from the protected-quote framework could see reduced order flow^[11]. For retail investors, the removal of trade-through protections means the best displayed price may no longer be guaranteed as an execution floor — shifting more responsibility onto broker-dealers’ best-execution obligations^[11].

FINRA is already moving in parallel. On July 24, 2026, the self-regulatory organization published Regulatory Notice 26-15, requesting industry input on potential changes to its best-execution rule, Rule 5310^[12]. The notice covers nine areas, including whether the NBBO will remain an important benchmark post-rescission, potential safe harbors for documented execution methodologies, the treatment of institutional versus retail orders, extended-hours trading guidance, and the implications of generative AI and tokenization for best execution^[12]. Comments are due September 25, 2026^[12].

The public comment period for the SEC’s Reg NMS proposal runs 60 days from Federal Register publication^[11]. Skadden’s analysis notes that “significant revisions to the proposal remain possible before a final rule is adopted,” given the breadth of affected market participants^[11].

Checklist: What to Monitor

What to Watch Next

The next two to four weeks will reveal how much of the 911 million unlocked SpaceX shares actually convert to sell orders — that volume-to-unlock ratio is the most important near-term data point for gauging lockup pressure on the staggered tranches that follow. If SPCX absorbs the supply without a meaningful break below the $108-110 zone (near the August 5 close), it would suggest the float expansion is being absorbed constructively. A break toward the $100 level or below would signal that sellers are overwhelming available demand and set up a more difficult environment for the subsequent unlock tranches.

Beyond SpaceX, the biotech IPO window remains the most active corner of the new-issuance market. Whether the 55% weighted average return holds as more deals price will determine whether the window stays open through the traditional late-summer pause. The September 25 FINRA comment deadline and the SEC’s Reg NMS comment window will shape the market-structure rules that govern how all of this new supply actually trades — a regime change that could matter more for execution quality and venue competition than any single IPO.

Goldman’s 2027 inflection point — when lockup releases and growing floats tip the supply-demand balance — remains the structural risk worth tracking. For 2026, the $1 trillion in buybacks provides a demand cushion. The question is whether that cushion holds as the staggered lockup calendar transitions from an engineering exercise into real, persistent selling.