Can the Market Absorb $200 Billion More in IPO Supply?

The U.S. equity market just put up the biggest first half for new issuance in history. Through June 26, 2026, U.S. issuers raised $251 billion in IPOs, surpassing the prior midyear record set during the 2021 listing boom, according to Renaissance Capital data reported by Reuters.{{cite:chatcmpltool}} Two transactions drove roughly 68% of that total: SpaceX’s $75 billion IPO on June 12 and Alphabet’s $85 billion follow-on equity raise to fund its AI buildout. Together, those two deals are larger than all U.S. IPO proceeds from 2023, 2024, and 2025 combined.{{cite:chatcmpltool}}

Strip out the headline names and the market is still record-paced. Renaissance Capital’s Q2 2026 review counted 48 IPOs in the quarter alone, raising $104.9 billion — the largest single-quarter total since 2021, even excluding SpaceX.{{cite:chatcmpltool}} Nine other IPOs cleared the $1 billion threshold, led by AI chipmaker Cerebras Systems, which opened roughly 89% above its offer price on its May 14 debut.{{cite:chatcmpltool}} UBS puts the full-year issuance trajectory at $200–350 billion.{{cite:chatcmpltool}}

The question for the second half is not whether companies want to issue. It is whether the market can absorb the supply without a repricing.

The SpaceX Lockup Overhang

SpaceX’s IPO priced at $135, opened at $150, and closed its first session at $161 — a 19% first-day gain that eased concerns about a botched debut.{{cite:chatcmpltool}} The stock currently trades at $162 as of the July 2 close,{{cite:chatcmpltool}} but the path has been volatile: across a four-session stretch in late June, SpaceX shed roughly $400 billion in market capitalization, including a single-day decline of about 16%.{{cite:chatcmpltool}}

The next test comes in August. SpaceX structured its lockup differently from the standard 180-day blanket restriction. According to the company’s S-1 filing, after SpaceX reports its first earnings as a public company — for the quarter ending June 30 — insiders can sell up to 20% of their eligible locked-up shares. If the stock is trading at least 30% above the IPO price at that point, they can sell an additional 10%.{{cite:chatcmpltool}} A rolling schedule then releases another 7% at each of the 70, 90, 105, 120, and 135-day marks post-IPO. After the second earnings report (for the quarter ending September), an additional 28% unlocks. Whatever remains is fully released at 180 days.{{cite:chatcmpltool}}

Founder Elon Musk is excluded from all early-release provisions and remains locked up through the full 180-day period.{{cite:chatcmpltool}}

The phased structure is designed to prevent a single-day supply shock, but it front-loads selling pressure into August. Multiple outlets report August 6 as the date investors are watching — likely SpaceX’s first earnings release, which would trigger the initial 20% (plus a conditional 10%) unlock.{{cite:chatcmpltool}} Former SEC Chair Gary Gensler has publicly described the period as a potential “Great Rebalancing” as early backers take profit.{{cite:chatcmpltool}}

I’d put the probability of meaningful post-unlock selling pressure at roughly 65/35. The 65% case rests on a simple fact: SpaceX’s early investors are sitting on enormous unrealized gains, and the phased structure explicitly gives them an exit ramp. Even a fraction of eligible holders selling 20% of their position introduces supply the market has never had to absorb for this stock. The 35% case requires that index-inclusion buying — SpaceX’s accelerated float expansion was designed to speed Nasdaq-100 eligibility — offsets the selling, and that the stock’s 30%-above-IPO trigger (which unlocks the extra 10%) fails to clear, keeping the release smaller.

The Pipeline Behind the Pipeline

The SpaceX unlock is the near-term variable. The structural variable is what comes next.

Anthropic confidentially filed its S-1 with the SEC on June 1, 2026, at an approximate $965 billion valuation.{{cite:chatcmpltool}} OpenAI followed on June 8, filing confidentially at an approximate $852 billion mark.{{cite:chatcmpltool}} Goldman Sachs and Morgan Stanley are bookrunning both deals, each expected to raise at least $60 billion.{{cite:chatcmpltool}}

But the timeline is uncertain. CNBC reports that OpenAI has not yet held pre-IPO meetings or set an official timeline, and The New York Times reported the company is leaning toward a 2027 listing.{{cite:chatcmpltool}} Anthropic’s timeline is similarly undisclosed. The confidential filings establish that both companies are in the queue, not that they are imminent.

The AI infrastructure layer is also feeding the pipeline. Lambda, an Nvidia-backed cloud provider, has been in talks to raise $350 million in pre-IPO funding and is targeting a public listing in the second half of 2026.{{cite:chatcmpltool}} The pattern is consistent: companies building AI compute capacity are tapping the largest available pool of capital — public equity — to fund multi-hundred-billion-dollar buildouts.

If both OpenAI and Anthropic price in late 2026 or early 2027 at the rumored deal sizes, the market would need to absorb another $120 billion-plus in AI-linked equity on top of the $251 billion already raised. That is the supply-side of the equation.

The Demand Side: Record Inflows, but Fragile

June 2026 saw approximately $150 billion in U.S. equity fund inflows — the largest single-month figure on record.{{cite:chatcmpltool}} Combined flows into U.S. equity, bond, and money market funds exceeded $170 billion in one week alone.{{cite:chatcmpltool}}

Barclays strategist Emmanuel Cau reads this not as a vote of confidence but as a FOMO-driven crowding signal, arguing that record inflows cap upside and amplify downside risk heading into Q2 earnings season.{{cite:chatcmpltool}} Goldman Sachs has separately warned that U.S. stocks are “extremely crowded” and that volatility risk is accumulating.{{cite:chatcmpltool}}

The historical base rate here is worth weighing. In 2021, the last comparable issuance cycle, record inflows and SPAC-driven supply coincided with a market that absorbed the paper and kept rising — until sentiment turned in early 2022 and the new-issue window slammed shut. The 2021 parallel is imperfect: this cycle’s supply is concentrated in a handful of mega-deals rather than spread across hundreds of SPACs, and the AI capex narrative provides a fundamental demand story that the 2021 SPAC boom lacked. But the crowding signal is the same shape.

The Buyback Bid Is Fading

The other side of the demand equation — corporate buybacks — is softening at exactly the wrong moment.

Absolute buyback value ticked to a nominal record in 2026, but growth has slowed sharply. Tech hyperscaler repurchase activity is down 64% year over year, per JPMorgan Asset Management.{{cite:chatcmpltool}} Bank of America Global Research notes that aggregate S&P 500 buybacks as a percentage of market cap have slid to their lowest level since late 2023.{{cite:chatcmpltool}}

The mechanism is straightforward: AI capex is winning the capital allocation battle. Operating cash flow that once funded share repurchases is being redirected toward data center buildouts, silicon procurement, and R&D. Wall Street Horizon data shows total corporate buyback announcements across more than 11,000 global firms near their weakest nominal level since before the pandemic.{{cite:chatcmpltool}}

This matters for the supply-demand balance. In past issuance cycles, corporate buyback demand served as a persistent bid that helped absorb new equity. If the buyback bid is structurally weaker — because cash is flowing into AI infrastructure instead of share repurchases — the market has less of a natural buyer for the paper coming down the pipe. Deutsche Bank argues that broad buybacks outside the hyperscalers remain intact, but the question is whether that is enough.{{cite:chatcmpltool}}

Market Structure: The 23-Hour Trading Day

The plumbing is changing underneath all of this. On April 10, 2026, the SEC approved Nasdaq’s proposal to extend trading hours to 23 hours per day, five days per week, divided into a Day Session (4:00 a.m. to 8:00 p.m. ET) and a Night Session (9:00 p.m. to 4:00 a.m. ET).{{cite:chatcmpltool}} Cboe EDGX received similar approval on May 29, 2026.{{cite:chatcmpltool}} NYSE Arca had already filed and received SEC approval in February 2025 and is working toward a 2026 launch.{{cite:chatcmpltool}}

The near-round-the-clock schedule is designed to capture global demand — but it also fragments liquidity. Thinner overnight books mean wider spreads and higher volatility during off-hours sessions, precisely when post-lockup selling or IPO aftermarket trading might occur. For newly listed stocks with small floats, the 23/5 structure could amplify the kind of violent swings SpaceX experienced in late June.

What to Watch Next

The base case is that the market absorbs the supply — inflows are at records, the AI narrative is intact, and the phased lockup structure prevents a single-day shock. The risk case is that the convergence of SpaceX unlock selling, the OpenAI-Anthropic pipeline, fading buybacks, and crowded positioning creates a supply-demand mismatch that forces a repricing of the new-issue cohort. Which case prevails depends on whether Q2 earnings deliver the AI revenue growth that justifies the valuations at which these companies are coming public. That is the variable to watch.