SpaceX Lockup Holds, But the Real Supply Test Is Still Coming

SpaceX’s first lockup expiry on August 6 was supposed to be a supply shock. More than 911 million shares — exceeding the 639 million sold in the IPO — became eligible to trade, potentially more than doubling the public float in a single day^[1]. Instead, the stock stabilized and rallied through the rest of the week^[2]. SPCX closed at $138.74 as of the 16:00 ET print on August 10, up 4.2% on the day^[3].

That is the good news. The harder question is what happens when the next tranches arrive — and when the broader AI-IPO wave shifts the supply-demand balance that has quietly supported US equities for a decade.

The staggered lockup: a meter, not a dam

SpaceX’s underwriters replaced the standard 180-day lockup with a tiered release schedule designed to meter selling rather than bottle it up for a single day^[4]. The structure is unusual and worth mapping precisely:

Sources: CNBC^[5], Reuters^[1].

Mizuho analysts noted that shares becoming eligible for sale does not mean the full tranche will be offered into the market^[5]. So far that has held: the stock absorbed the first wave without breaking. But Robert Hackal, CEO of institutional brokerage R.F. Lafferty & Co., told Reuters he had been fielding calls from pre-IPO investors eager to sell SpaceX holdings and rotate into other upcoming IPO candidates including Anthropic, OpenAI, and Anduril Industries^[1]. Some selling is clearly happening; the question is pace.

The structural wrinkle is that SpaceX’s float is small relative to its roughly $1.43 trillion market capitalization^[5]. Even modest selling pressure from unlocked insiders can move the price disproportionately — which is exactly why options premiums on SPCX have reached levels one advisor called “sheer insanity”^[1].

Goldman Sachs: supply is normal, buybacks are bigger

Goldman Sachs Research frames the issuance surge as a return to normal rather than a market-threatening flood. Ben Snider, chief US equity strategist, noted that roughly 50 US IPOs priced in the first half of 2026 — about double the same period in 2025 — with dollar volume of approximately $120 billion, already tying 2021’s full-year record^[6].

The key demand-side offset: Goldman forecasts total 2026 equity issuance (IPOs plus follow-ons) of approximately $700 billion, which scales to about 1% of the total US equity market — below the long-term average and roughly in line with 2015–2019 levels^[6]. Meanwhile, corporate buybacks are projected to exceed $1 trillion this year, meaning corporate demand for shares outweighs corporate supply of shares before even counting retail, hedge fund, or mutual fund demand^[6].

Snider’s admission, though, is the part worth marking: “the math does get harder in 2027.” IPOs are coming public with relatively small floats, but over time more shares will enter the market as lockups expire, and that suggests “potentially a lot more supply as we look into 2027 and beyond”^[6].

US corporations raised $252 billion in equity issuance through mid-2026, with the uptick driven largely by financing needs tied to AI investment^[7].

Ninety One: the de-equitisation tailwind is ending

Where Goldman sees absorption, Ninety One’s Investment Institute sees a structural reversal. Sahil Mahtani and Daniel Morgan published research in late July arguing that two decades of net buybacks — companies repurchasing more stock than they issued — shrank the US equity supply and added roughly 0.7% annually to returns from 2015 through 2025^[4].

Their central claim: SpaceX, OpenAI, and Anthropic collectively raising $200–250 billion at listing represents only about 0.3% of a $75 trillion market — real money, but not enough to move it in the short term^[4]. The larger risk is the float expansion that follows. Companies typically float roughly a quarter of shares at IPO; within two years, that tends to grow to around 70%^[4]. Applied to SpaceX, Anthropic, and OpenAI, that could mean close to $4 trillion in additional shares reaching the market — a 4% expansion of US public equity^[4].

Ninety One modeled three scenarios using its Capital Markets Assumptions framework:

Source: Ninety One Capital Markets Assumptions^[4].

The mechanism that could bring the overhang earlier than 2027 has two parts. First, index providers are loosening admission rules: Nasdaq implemented changes that allowed SpaceX to join the Nasdaq 100 just 15 trading days after its IPO, with relaxed float and market-cap requirements^[4]. Second, deal structures like SpaceX’s staggered lockup are designed to grow the tradeable float faster than the traditional 180-day model^[4]. Index inclusion obliges passive funds to buy at whatever weight the float dictates, and a rising float means rising forced demand — but also a rising supply of shares for those funds to absorb.

The options market says: positioned for more upside

The supply-demand debate is happening against a backdrop of extraordinary bullish positioning. In the week ending August 8, the S&P 500 surged above 7,700 for the first time, posting a 3.6% weekly advance. More than four million S&P 500 index calls traded on Cboe on Tuesday alone — a record, topping the previous high from May by 10%^[2].

The put-to-call ratio across all options plunged to 0.83, the second-lowest reading on record and well below the average above 1.0 that reflects puts’ primary use as hedges^[2]. Total S&P 500 open interest ended the week at 27.4 million contracts, in the 93rd percentile over the past year, with call open interest in the 95th percentile^[2]. The VIX fell to its lowest level since January^[2].

The largest open-interest strike in SPY is the 760-strike (about 1.7% below Friday’s close), where 94,000 open puts could create support on dips. On the upside, the biggest call concentration is at the 785-strike, with 114,000 open calls^[2].

What to watch next

1. August 20 SpaceX tranche (~319M shares). The first expiry held, but that was the one most anticipated. The second tranche arrives in 10 days and will test whether early stability was real absorption or just a slow start.

2. Anthropic IPO pricing and float. Anthropic is scheduling investor meetings with Goldman Sachs, Morgan Stanley, and JPMorgan Chase, and was last valued at $965 billion^[8]. The float percentage it chooses at listing will be the first concrete data point on whether the AI-IPO cohort is structuring deals to grow float quickly — the Ninety One thesis in action.

3. OpenAI timeline. OpenAI has not held pre-IPO meetings or set an official timeline^[8]. Reuters reported a target valuation of up to $1 trillion and a possible September debut^[8], but the New York Times and CNBC reported the company is leaning toward 2027^[8]. The gap between those timelines is itself a signal: if OpenAI waits, the 2027 supply wall Goldman flagged gets steeper.

4. Q3 2026 buyback announcements. Goldman’s $1 trillion buyback forecast for 2026 assumes corporate demand stays elevated. Q3 earnings season — starting in October — will bring fresh authorization announcements. If buyback pace slows while lockup tranches accelerate, the absorption math flips.

5. Nasdaq 100 and S&P 500 inclusion mechanics. SpaceX’s 15-day Nasdaq 100 admission set a precedent. Whether the S&P 500 follows with similar float-relaxation for incoming AI names will determine how quickly passive flows must absorb new supply.

The base case — Goldman’s — is that buybacks and investor demand absorb the 2026 issuance wave without disruption. The tail case — Ninety One’s — is that the two-decade de-equitisation tailwind reverses, and the math for US equity compounding gets meaningfully harder over the next decade. These are not contradictory: both can be right for 2026, and both can diverge starting in 2027 when the float expansion accelerates. The probability I would assign to a smooth absorption through 2027 is roughly 60/40 — favorable but not overwhelming, and the 40 case is not a gentle slowdown but a structural shift in the supply of US public equity. The next two lockup tranches and the Anthropic IPO float will tell us which trajectory we are on.