The Supply Test: SpaceX Lockups and the End of Equity Scarcity

For nearly two decades, the US equity market has been defined by a quiet but powerful force: shares disappeared. Between 2006 and 2025, JPMorgan estimates net US equity issuance was roughly negative $430 billion – meaning companies retired more stock through buybacks than they created through IPOs and secondaries combined. This “de-equitization” reduced the float available to investors and put a persistent bid under share prices.^[1]

That era is ending. JPMorgan now forecasts that approximately $1.5 trillion of new stock supply will hit US equity markets over the next two years, driven by the SpaceX IPO, Alphabet’s announced share issuance, and a pipeline of mega-listings including OpenAI and Anthropic.^[1] It would mark one of the heaviest issuance cycles since the late 1990s dot-com era, and it arrives just as corporate America’s buyback machine – which absorbed supply for two decades – shows the first signs of fatigue.

SpaceX: The First Real Stress Test

SpaceX went public on approximately June 11, 2026, listing on Nasdaq under the ticker SPCX at $135 per share. The IPO raised roughly $75 billion and pushed the company’s valuation past $2 trillion, making it the largest public offering in US history.^[2]

But less than 5% of SpaceX’s total shares were actually released into the public float at launch.^[2] Rather than the standard 180-day lockup that most IPOs use, SpaceX implemented a staggered release schedule: tranches of roughly 7% unlock at days 70, 90, 105, 120, and 135 after the IPO, with larger waves tied to earnings reports.^[3]

The first major unlock hits shortly after SpaceX reports Q2 earnings in early August, releasing between 20% and 30% of total shares – roughly 911.5 million shares valued at approximately $123 billion at recent prices.^[2] A second tranche of about 28% follows after Q3 earnings. By the full 180-day mark in December 2026, roughly 40% of all SpaceX shares will be freely tradable.^[2] Elon Musk’s shares carry a 366-day lockup, meaning he cannot sell until approximately June 2027.^[2]

The stock has already slipped to the $124-$135 range, below its IPO price and down roughly 33% from its post-IPO high.^[2] An aborted Starship launch attempt on July 17 added to the pressure, with the stock falling 3% to around $131 – an all-time low for its brief public life.^[4] The timing is uncomfortable: the first major supply wave lands while the stock is already testing its debut price.

The Phased Unlock at a Glance

Figures are approximate and based on reporting of SpaceX’s S-1 filing structure.^[3] The key takeaway: by early August, the tradable float could more than quadruple.

The Buyback Counterweight – Strong, but Showing Cracks

On one side of the ledger, corporate buybacks are running at record levels. S&P 500 companies announced $665 billion in repurchase programs during the first four months of 2026, the highest total ever recorded for that period. Full-year authorizations are forecast to reach $1.55 trillion.^[5]

Recent examples underscore the pace: Dollar Tree replenished a $2.5 billion authorization on July 2, Morgan Stanley reauthorized a massive $20 billion buyback on June 24, and Accenture added $2 billion to its program on June 23 – a combined $24.5 billion in new buyback capacity from just three companies.^[5]

But Fidelity’s Director of Global Macro, Jurrien Timmer, argues the buyback era may be peaking. He observes that corporate share repurchases are declining as a percentage of earnings while share counts are rising – a reversal of the de-equitization dynamic that has supported equity prices since 2009.^[6] The surge in AI capital expenditure is redirecting corporate cash from buybacks toward data centers and compute infrastructure.^[6]

Deutsche Bank pushes back on the bearish read, arguing that AI capex has not and likely will not crowd out buybacks across the broader S&P 500, since the five largest cloud firms drive most of the capex increase while the rest of the index continues repurchasing.^[7] Goldman Sachs similarly projects buybacks will hit record levels in 2026, exceeding new stock supply.^[7]

The tension between these views is the crux: buybacks are still massive in absolute terms, but the direction of travel – rising share counts, heavy capex commitments, and a record issuance pipeline – is shifting the supply-demand balance for the first time in two decades.

The IPO Pipeline: Not Just SpaceX

The current week’s IPO calendar shows the breadth of new supply. Jersey Mike’s Subs filed to raise $1 billion in its IPO on July 30, underwritten by a syndicate of more than 20 banks led by Morgan Stanley, Jefferies, and JPMorgan.^[8] Reformation Inc., a fashion brand, plans a $225 million offering the same day.^[8] Scribe Therapeutics, a gene-editing biotech backed by Leerink, Goldman Sachs, and Guggenheim, targets $100 million on July 24.^[8] Several SPACs are also pricing this week.^[8]

Beyond new listings, the secondary offering market remains active: REGENXBIO announced a $100 million underwritten secondary on July 16.^[9] Lockup expirations for other recent IPOs are also hitting the calendar: BitGo Holdings (BTGO) lockup ends July 21, EquipmentShare (EQPT) on July 22, and Ethos (LIFE) on July 28.^[10]

What Citadel’s Market-Structure Team Sees

Scott Rubner, head of equity and equity derivatives strategy at Citadel Securities, published a 1H 2026 review arguing that “markets entering the second half of 2026 bear little resemblance to the markets investors navigated for most of the past two decades.”^[11] The defining story, in his telling, is not a single macro event but the structural transformation of equity markets – concentrated positioning, shifting flows, and the mechanics of how supply meets demand.^[11]

Rubner had already flagged flow fragility in May, warning that the S&P 500’s roughly 17% rally from the March 30 low – adding about $10 trillion in market value – left the market vulnerable to a flow-of-funds unwind.^[11] The concern is not just about fundamentals; it is about whether the plumbing can absorb the supply now coming down the pipe.

What to Watch Next

1. SpaceX Q2 earnings (early August): The first lockup wave lands within days of the earnings report. If the stock is below the $135 IPO price, insider selling pressure intensifies. If results impress, demand may absorb the initial wave. Watch the volume profile in the days following the unlock.

2. Buyback execution vs. authorization: Announced buybacks ($1.55 trillion in 2026 authorizations^[5]) are not the same as executed buybacks. Track quarterly 10-Q repurchase disclosures to see whether companies are actually buying or simply holding authorizations as optionality.

3. Net share count trend: Timmer’s thesis hinges on whether S&P 500 aggregate share counts are rising for the first time in years.^[6] The Q2 earnings season – now underway – will provide the next data points.

4. OpenAI and Anthropic IPO timing: If either files in H2 2026, the supply wave compounds. The market’s reaction to SpaceX’s lockup will be read as a signal of appetite for the next mega-listing.

5. Index-inclusion flows for SPCX: SpaceX’s phased lockup was partly designed to accelerate Nasdaq 100 inclusion, which would trigger forced buying from index funds.^[3] The timing of that inclusion and the resulting flows could partially offset lockup selling pressure.

The base case is that record buybacks and index-inclusion flows absorb much of the new supply. But the risks to that case are accumulating: a stock already below its IPO price, a buyback engine showing deceleration in net terms, and a pipeline that extends well beyond a single listing. The market has not faced a supply test of this magnitude in two decades. Whether it passes will shape the H2 2026 narrative more than any earnings beat or macro datapoint.