The Surprising Top Winners of Anthropic’s Upcoming IPO

A historic multi-billion-dollar payout is on the table for swathes of early backers once leading AI developer Anthropic debuts on public markets. Marquee venture capital firms including Menlo Ventures, Sequoia, Sound Ventures, and Spark Capital are all positioned to book massive returns on their early stakes — but the company’s newly released S-1 filing reveals a quirk that breaks decades of standard tech IPO precedent: not a single one of these blue-chip VC firms holds a 5% or larger ownership share, the minimum threshold required to be listed in Anthropic’s official principal stockholders table.

This is almost unheard of for a high-flying late-stage startup. For most typical tech IPOs, lead venture investors hold double-digit percentage stakes in the companies they backed through their high-growth early years. The anomaly here traces directly to Anthropic’s staggering size. At its current $965 billion private valuation, a 1% slice of the company is worth nearly $10 billion. Per recent Bloomberg reporting, Menlo Ventures’ roughly $14 billion total position in Anthropic works out to only ~1.5% ownership — a massive absolute dollar value that still lands well below the 5% cutoff for the principal stockholder list.

Where traditional venture players lack outsized proportional stakes, Anthropic has reserved massive ownership positions for its core strategic partners: corporate backers that also serve as key operational vendors to the AI firm. By far the single largest financial beneficiary of the upcoming IPO is set to be Amazon.

Amazon first backed Anthropic in 2023 with an initial pledge to invest up to $4 billion into the AI startup, and has since poured billions more in additional capital. Rather than purchasing stock upfront, the retailer structured the vast majority of its early investment as convertible notes: a form of debt that converts to equity shares automatically upon an IPO or acquisition. As of June 30, Anthropic’s S-1 shows Amazon holds $6.2 billion in outstanding principal on those notes, which makes up 100% of the AI firm’s total debt load. As Anthropic’s valuation exploded across consecutive funding rounds, however, the equity those notes will convert into grew exponentially more valuable. Amazon’s own regulatory filings value its note holdings at $97.9 billion as of mid-year.

That sharp surge in fair value forced Anthropic to record the ballooning size of its outstanding liability on its own books. The company logged a $72.4 billion non-cash charge on its first-half 2026 income statement under the line item “change in fair value of convertible notes, derivative liabilities, and SAFEs”, meaning no actual cash left Anthropic’s accounts to cover the adjustment.

Per the S-1, Amazon’s notes are eligible to convert into as many as 1.84 billion total shares, though a pre-set ownership cap restricts the tech giant to a maximum 12% stake of Anthropic’s partially diluted share count — a calculation that accounts for authorized but not yet issued shares such as employee stock options. Amazon retains the right to waive that cap, and any notes that cannot convert at the IPO will remain outstanding and convert in subsequent quarters, still subject to the same 12% limit. The convertible notes are far from Amazon’s full holdings, though: the company’s Q2 report for the period ending June 30 shows it poured an additional $10 billion into non-voting preferred stock across Anthropic’s two most recent funding rounds, splitting $5 billion across each. When combined with the $8 billion total Amazon deployed via notes between 2023 and 2025, its total hard capital outlay for the stake comes to roughly $18 billion. On top of its massive paper equity gains, Amazon will continue to lock in steady nine- and ten-figure recurring revenue from Anthropic’s binding pledge to spend at least $110 billion on AWS cloud infrastructure over the next 10 years.

Google is also positioned to reap a historic windfall, both from its Anthropic equity stake and its own long-term cloud agreements with the AI firm. Per court filings cited by The New York Times from early last year, Google held roughly 14% of Anthropic at that point, and has deployed additional capital since, including a $10 billion investment announced this past April. Those massive subsequent funding rounds have since diluted its holding, with PitchBook analyst Harrison Rolfes telling TechCrunch he estimates Google’s current fully diluted stake sits closer to 8%. The search giant has also secured a binding cloud commitment from Anthropic worth at least $114 billion through 2033.

While the multi-billion-dollar payouts in store for traditional venture backers are nothing to scoff at, the S-1 makes clear the biggest winners of Anthropic’s landmark public debut are not the early VC firms that wrote small early checks, but deep-pocketed tech giants that backed a potential long-term rival early, and now also act as Anthropic’s largest vendors for the compute power its generative AI models require. The S-1 itself explicitly flags a key associated risk: those very cloud providers operate their own competing generative AI model lines, meaning their long-term incentives may not always align with Anthropic’s own strategic priorities.

Note: The estimate for Google’s fully diluted Anthropic stake has been updated to reflect latest public market data.