AI Megadeals Swallowed 87.5% of All US Venture Dollars in H1 2026

The numbers from PitchBook’s Q2 2026 US VC Valuations report, published on August 10, are staggering in their clarity. In the first half of 2026, US venture capital deal value reached $412.7 billion — already exceeding the full-year total for 2025 by 30%. And of that enormous sum, megadeals of $100 million or more consumed 87.5% of every dollar deployed. The remaining 12.5% — roughly $51.6 billion — was left to fund every other startup in America.

This is not a gradual shift. It is a structural reallocation of capital at a scale the venture industry has never seen.

The AI Premium: 6.6x at Series D

The concentration is overwhelmingly driven by artificial intelligence. PitchBook’s data shows the “AI premium” — the valuation gap between AI and non-AI companies — widening at every stage. At Series A, AI pre-money valuations run roughly double those of non-AI peers. By Series D and later, that ratio explodes to 6.6x.

Emily Zheng, a senior research analyst at PitchBook, highlighted the velocity of late-stage value creation. In 2025, the median velocity of value creation at Series D and beyond was $108.9 million. In the first half of 2026, it reached $1,028 million — close to a tenfold increase in twelve months.

“Top AI companies like Anthropic are driving this growth, as its valuation grew 5.3x in just eight months,” Zheng told Fortune. Median AI pre-money valuation at Series D and later now sits at $3.95 billion. Meanwhile, AI companies posted a median valuation step-up of 2.2x this year, compared to 1.6x for non-AI companies.

Three Companies, 67% of the Capital

The Q1 data from PitchBook’s earlier report tells an even more concentrated story. Of the 1,546 deals recorded in Q1 2026, just three companies — OpenAI, Anthropic, and xAI — accounted for 67.3% of all AI capital deployed. The remaining $83.5 billion was split across every other AI startup in the market.

By H1, three venture firms alone accounted for 48% of all venture capital raised. The money funding this explosion is increasingly not traditional venture money at all. Nontraditional investors participated in 91.9% of US VC deal value this year, and corporate venture arms were involved in 82.6%. On the secondary platform Hiive, the top 20 startups accounted for 86% of second-quarter value, with the top five alone taking 50.3%.

The Vintage Discount: 2021 Companies Trade 59% Below Par

Perhaps the most striking finding in the report is what happened on the secondary market. On Forge Global’s platform, companies whose last primary round was in 2026 trade at no discount. For 2025-vintage companies, the median discount is 4.7%.

Then the floor drops out. Companies that last raised in 2021 trade at a median discount of 59.1%. For 2022, it is 54.1%. Two businesses with identical revenue and growth profiles can receive wildly different prices — the only difference being the year stamped on their last term sheet.

PitchBook explains the mechanism: stale primary rounds lack a fresh reference point, and secondary buyers have limited information rights. Without a recent price discovery event, there is nothing to anchor expectations against.

The real-world consequences are already visible. Capital One acquired Brex for $5.2 billion — a steep drop from the fintech’s pandemic-era peak valuation of $12.3 billion. That 58% discount falls squarely within the secondary market band for 2021-2022 vintages.

SpaceX: The IPO That Carried the First Half

No single entity shaped the H1 landscape more than SpaceX. The company went public, acquired xAI in a $250 billion deal, and announced a $60 billion all-stock acquisition of AI coding startup Cursor (parent company Anysphere). Its valuation rocketed from $180 billion to $1.8 trillion in under two years.

But the post-IPO performance has been rocky. SpaceX priced at $135 per share and traded around $115 in late July — down 14.8% from its listing price. Of the ten most notable public listings since 2025, only three trade above their IPO price: Cerebras, CoreWeave, and Circle. Three others are down more than 50%.

PitchBook’s assessment of the IPO market is blunt: a single record-setting listing is not enough to reopen the window for venture-backed exits.

The Unicorn Count: 945 and Climbing

The active unicorn count hit a record 945 in the second quarter, up 9.4% since the end of 2025. Their aggregate valuation reached $5.3 trillion. The report notes dryly: almost none of that value has been realized through liquidity events.

Nineteen startups crossed the $10 billion valuation mark during the period, further concentrating value at the apex. Acquisitions did show genuine improvement, with deal value reaching $375.4 billion — a decade high. The median acquisition step-up recovered to 1.9x from 1.2x, and median acquisition size doubled to $200 million. ServiceNow’s $7.8 billion acquisition of Armis and Eli Lilly’s $7 billion deal for Kelonia Therapeutics were among the standout transactions.

What This Means for the Startup Ecosystem

The data paints a bifurcated market. On one side, a handful of AI companies with frontier-scale ambitions are absorbing nearly all available growth capital, backed by sovereign wealth funds, corporate strategics, and mega-funds willing to write nine-figure checks. On the other, the vast majority of startups — including promising non-AI businesses — face a funding environment where flat and down rounds have fallen to 13.1% (the lowest since 2022) but where the bar to participate in the upside has never been higher.

Even the firms sounding the alarm are complicit. Index Ventures raised $2 billion for AI while co-founder Neil Rimer warned of a coming redistribution of AI wealth. Accel raised $5 billion for late-stage AI in April and added another $3.5 billion in August. The firms cautioning about concentration are the same firms funding it.

The real test, as PitchBook notes, comes down to two numbers: whether 87.5% holds as the megadeal share, and whether the 59.1% vintage discount for 2021 companies narrows. Both answers arrive in the next report. For now, the message to founders outside the AI megadeal bracket is clear: the capital exists, but the door is narrowing.