Anthropic IPO: what UK investors need to know

Frontier AI lab Anthropic is set for a place among Wall Street's top ten companies as the start-up behind the Claude next generation AI assistant moves towards a potential $2 trillion (£1.5 trillion) stock market listing.

At this reported valuation, the pureplay AI company will exceed June's $1.75 trillion record-breaking initial public offering (IPO) by Elon Musk's Space Exploration Technologies Corp Class A (NASDAQ:SPCX).

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The listing is likely to take place after November's US mid-term elections, which will mean that Anthropic gets in ahead of ChatGPT firm OpenAI after both filed IPO paperwork back in June.

The debut will represent another landmark for a company whose AI models have shaken the valuations of FTSE 100 companies including RELX (LSE:REL), London Stock Exchange Group (LSE:LSEG) and Sage Group (The) (LSE:SGE).

No company in history has grown organic revenue at such a scale and pace, having generated its first dollars as recently as 2023. It was founded in 2021 by former members of OpenAI, with their mission rooted in the belief that advanced AI must be developed responsibly.

Revenue rose 14-fold year-on-year to $11.5 billion in the second quarter of this year, while the annual run-rate figure of $65 billion compared with $9 billion at the end of 2025.

A successful IPO will reward early backers including Amazon.com Inc (NASDAQ:AMZN) and Google owner Alphabet Inc Class A (NASDAQ:GOOGL), as well as holders of Baillie Gifford's Scottish Mortgage Ord (LSE:SMT) and Baillie Gifford US Growth Ord (LSE:USA) trust.

Scottish Mortgage said recently: “Anthropic has delivered one of the most remarkable growth stories in the history of enterprise software. It has had a revenue trajectory with no real precedent in business-to-business technology.”

However, the IPO comes at a time of heightened worries over the pace of the technology's advance and whether the growth behind Wall Street's AI trade is sustainable.

What does Anthropic do?

From start-up to a potential valuation of $2 trillion in the space of five years, Anthropic has become the fastest scaling software company in history.

It was founded in 2021 by seven former OpenAI executives, including the siblings Dario and Daniela Amodei, as an AI safety and research company. “We want AI to be safe and beneficial for our users and for society as a whole,” it said.

The Public Benefit Corporation's explosive revenues growth has been built on the March 2023 launch of Claude, an AI assistant based on the company's research into training AI systems.

Claude Code, which helps software developers write and deploy code, followed in May 2025 before January's launch of Claude Cowork.

Claude is now available across the world’s three largest cloud platforms – Amazon, Google and Microsoft Corp (NASDAQ:MSFT) - meaning that enterprise customers can access Anthropic’s models inside the cloud environments they already use.

The launch of Anthropic’s Opus 4.5 model in November 2025 transformed Claude's capabilities through autonomous, agentic AI workflows.

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The potential changes to how work gets done fuelled worries about the durability of traditional software companies such as Relx, London Stock Exchange or The Sage Group.

Scottish Mortgage said the agentic developments marked the third era of generational AI after the conversational era of OpenAI’s ChatGPT in late 2022 and the reasoning era when models learned to think through problems step by step.

It added earlier this year: “Models could now be given a goal and work towards it over many steps: planning, using tools, checking their work and producing useful outputs without constant human prompting. Each era has built on the last rather than replaced it.

“Today’s agents are reasoning models that have learned to act, just as reasoning models were conversational models that had learned to think.”

What about Anthropic's financial performance?

Just over three years after earning its first dollar, the company is reported to have told a group of investors that its annual revenue run-rate topped $65 billion at the end of July.

That compares with $47 billion in its last public disclosure in May, $14 billion in February and $1 billion in January 2025.

The trajectory means that Anthropic is projecting 2028 ​revenue of roughly $190 billion to $200 billion, according to Reuters.

Two years ago, a dozen customers spent over $1 million with Anthropic on an annualised basis but by February this figure exceeded 500 and had doubled again to 1,000 by April.

Eight of the Fortune 10 are now Claude customers, while a strategic partnership with Microsoft in November 2025 has made Claude the only frontier AI model available across Amazon Web Services, Google Cloud and Azure.

Other financial milestones include two consecutive positive quarters of adjusted operating income, with the Financial Times reporting that Anthropic's gross margin topped 80%.

However, these figures exclude revenue shared ​with distribution partners such as Amazon and the huge amount of spending required to train Anthropic's frontier models.

Potential investors will have to wait until the release of the IPO prospectus to discover the extent of the company's current losses and other key metrics such as free cash flow.

When's the IPO likely to take place?

Anthropic filed confidential IPO documents with the US Securities and Exchange Commission (SEC) on 1 June, just a few days before its biggest competitor OpenAI did so.

Under the rules of the SEC, the public S-1 prospectus must be released at least 15 days before the company begins marketing shares to investors.

A listing window in mid-October had been seen but the Wall Street Journal (WSJ) recently reported that November was now the most likely date.

This would enable the company to present third-quarter financials and potentially allow for the release of a new AI model that could bolster the valuation ahead of its public debut.

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The WSJ said the change of timing was not related to September's public warning by a former Anthropic researcher that triggered debate about whether AI advancements are moving too fast.

OpenAI, meanwhile, is not set to go public until 2027.

The ChatGPT firm has reportedly held talks with investors about another private funding round, which the Financial Times said could value the business at $1.2 trillion. In March, it last raised $122 billion at an $852 billion valuation.

A further OpenAI fundraising would have a potential impact on Anthropic's listing if it squeezes investor demand.

What's the likely IPO valuation?

A $2 trillion figure has been widely reported, which is based on plans to raise up to $100 billion in the offering. Both figures would exceed the records of $1.77 trillion and $85.7 billion set by SpaceX in its June IPO.

Ten-fold growth in the revenue run rate in each of the three years up to early 2026 highlights why some believe $2 trillion is achievable.

Based on forecasts for a revenue run-rate of $320 billion, Financial Times said this would mean just seven times its 2028 sales. That's a little less than Microsoft, while SpaceX is on 16 times.

Much will depend on what Anthropic says in its public filings about its total addressable market and the margin outlook, as well as the risk appetite of potential investors at a time of speculation about a possible slowdown in the rollout of new AI models.

The reported valuation of $2 trillion would make Anthropic the seventh or eighth largest company on Wall Street, placing it alongside SpaceX at just over $2 trillion.

NVIDIA Corp (NASDAQ:NVDA) is Wall Street's most valuable company at $5.6 trillion, followed by Apple Inc (NASDAQ:AAPL) at $4.7 trillion and Alphabet worth $4.1 trillion. Microsoft is valued at $3.7 trillion, Amazon at about $2.8 trillion and Taiwan Semiconductor Manufacturing Co Ltd ADR (NYSE:TSM) at $2 trillion.

The reported valuation represents a big jump from May's $965 billion, when one of the largest private funding rounds in history generated $65 billion for Anthropic.

Financial derivatives firm Marex Solutions said pre-IPO futures contracts, otherwise known as perpetuals or "perps", were then pointing to a figure comfortably above $1 trillion.

It said the contracts had shown to be effective in price discovery on two previous high-profile IPOs: Firstly, SpaceX priced its IPO at $135 while perps traded in the $170s, which is about where the stock touched in its debut session.

AI hardware and cloud computing company Cerebras was priced at $185 by its banks in its May IPO and opened at $350, within 1.3% of where the perps had it.

How has SpaceX performed since its IPO?

The shares of Elon Musk's SpaceX, which spans rocket launch services, Starlink broadband connectivity and social media and AI compute, have settled near the $150 a share mark.

They peaked at $225 shortly after the IPO before a descent to $105 in early August.

The recent rally followed second-quarter revenues of $7.8 billion, which helped SpaceX beat Wall Street earnings expectations by a margin of 75% after reporting a surplus of $3.5 billion.

A record 20% of the IPO shares were allocated to retail investors worldwide, including about 100,000 in the UK who spent a total of £271 million at the opening price of $135.

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Broker Marex, which oversaw the IPO process in the UK, said 61% of investors in the retail offer got their full allocation, with those who applied for up to $2,700 getting the full amount.

Indirect beneficiaries of the launch include holders of the Scottish Mortgage, US Growth and Edinburgh Worldwide Ord (LSE:EWI) investment trusts after Baillie Gifford participated in a December 2018 funding round that valued SpaceX at $31 billion.

Who owns Anthropic?

The seven co-founders each own just over 1.6% of the company, according to Forbes.

Early investors who stand to generate big upside from an IPO include Google owner Alphabet and Amazon, having backed Anthropic in 2023.

Their exact equity ownership percentages have not been disclosed but it is believed that Alphabet holds about a 14% stake and Amazon between 15% and 21%.

In November 2025, Nvidia committed to invest up to $10 billion as part of a “deep technology partnership” to support Anthropic's future growth.

At the same time, Microsoft committed $5 billion as part of an expansion of their existing partnership to provide broader access to Claude for businesses.

AI Funding Tracker estimates that Anthropic has raised roughly $125–132 billion across 18 funding rounds, adding that few companies in history have repriced as fast.

When it was founded in 2021, financial support came from a $580 million funding round.

A $3.5 billion funding round took place in March 2025, valuing the business at $61.5 billion. By September of the same year the Series F round raised $13 billion at $183 billion, followed by $30 billion at $380 billion in February and $65 billion at $965 billion in May.

The partnership with Amazon involved investment totalling $4 billion between September 2023 and March 2024, as well as the supply of compute by Amazon Web Services to Anthropic to build, train, and deploy its future frontier models.

The upper limit of Alphabet's ownership is capped at 15% to manage competition with Google's Gemini models.

The partnership includes a non-exclusive arrangement for the supply of compute capacity by Google to Anthropic and an agreement to distribute Anthropic frontier models (FM) on Vertex AI.

In 2024, the UK's Competition and Markets Authority (CMA) considered the extent to which Google’s expertise and status in the industry might allow it to exert substantially greater influence than might be suggested by its non-voting shareholding.

While the CMA said Google had a strong position throughout the FM supply chain and other adjacent areas, the regulator said other significant investors in Anthropic, including Amazon also have considerable expertise and status.

The CMA said: “In addition, other current shareholders are largely sophisticated investors or have their own technical expertise.”

Who else has Anthropic exposure?

Five investment trusts with Anthropic holdings have provided retail investors with a way of gaining exposure before the company is listed on the stock market.

Baillie Gifford holds the company in three of its funds, having first invested in the August 2025 Series F fundraising round that valued Anthropic at $183 billion. It has also participated in the two subsequent fundraisings in February and May this year.

Anthropic is now the fourth-largest holding in Baillie Gifford US Growth Trust, accounting for 6.8% of the portfolio at the end of August.

It is the fifth-largest in Baillie Gifford's SCHIEHALLION FUND LTD(THE) (LSE:MNTS) at 6.1% and the seventh-largest in the FTSE 100-listed Scottish Mortgage Investment Trust at 2.9%.

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Scottish Mortgage said that Anthropic generated a total return of 325% in the year to 30 June.

Manager Tom Slater added in April: “When Scottish Mortgage took a stake in August 2025, we knew we were backing a business that neither fully understood what it had created, nor could confidently forecast demand, even a year out.

“But Scottish Mortgage’s job isn’t to predict the future perfectly. If fund managers did that, stock prices would reflect all future information.

“Instead, we maximise the chances of making good decisions by recognising uncertainty, accepting that the range of potential outcomes widens the further out we peer – and then look for factors that let us build conviction.”

RIT Capital Partners Ord (LSE:RCP) and Pantheon International Ord (LSE:PIN) are also Anthropic investors, as they are in some of the world's other largest private companies including OpenAI and Databricks.

How is the company run?

Anthropic is a Public Benefit Corporation, whose purpose is the responsible development and maintenance of advanced AI for the long-term benefit of humanity.

The board of directors is elected by shareholders and Anthropic's Long-Term Benefit Trust, which is an independent body comprising five trustees with backgrounds and expertise in AI safety, national security, public policy and social enterprise.

A class of stock held by the Trust grants authority to elect and remove a number of Anthropic’s board members that will phase in according to time and funding-based milestones.

Anthropic said: “In establishing the Long-Term Benefit Trust we have, in effect, created a different kind of stockholder in Anthropic.

“Anthropic will continue to be overseen by its board, which we expect will make the decisions of consequence on the path to transformative AI.

“In navigating these decisions, a majority of the board will ultimately have accountability to the Trust as well as to stockholders, and will thus have incentives to appropriately balance the public benefit with stockholder interests.”

Scottish Mortgage points out that Anthropic places enormous importance on the role of founders.

Anthropic has seven, all of whom are still actively involved. They include chief executive Dario Amodei, who led the development of OpenAI’s GPT-2 and GPT-3 models before founding a company of his own.

Slater added: “In my conversations with Dario, I’ve been struck by his principled view that Anthropic must prioritise safety, whether in terms of discrimination, bias, child protection or mental health.

“This diligence may mean a conservative approach to product development. But it’s helped the firm avoid the pitfall of generating harmful and inflammatory material.”

What are the risks?

Rapid advances in recent offerings by Alibaba and DeepSeek highlight China's cut-price threat to Anthropic and OpenAI in the race for global AI leadership.

This potential disruption to Wall Street's AI trade was highlighted in early 2025 when Nvidia shares fell by as much as 17% in one session after a release by DeepSeek overhauled previous assumptions on the investment needed for sustaining the AI revolution.

Building AI models requires significant computing power, posing a significant risk as the cost of high-end chips and data centres continues to rise.

PitchBook senior analyst Harrison Rolfes, who has been covering Anthropic's IPO preparations, told Morningstar recently: “The biggest hurdles have to do with compute (processing power and memory) and energy.

“They need such a significant tap into data centres and the power grid in order to run a lot of these models.

“The second hurdle is the need to maintain a level of trust and accuracy so that people continue to use it. The third hurdle is to become integrated so deeply into these [client] enterprises that it would be almost impossible to switch, or it’d be impossible to continue working without using it.”

Meanwhile, City firm Panmure Liberum believes that the expectations priced into listed and unlisted AI companies are way too optimistic.

It believes the AI bubble will pop, but not this year as the world is not yet at the extremes in market behaviour. However, recent market developments suggest that we are starting to get into this phase.

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Panmure noted: “The key reason why we think AI is in a bubble is that we think investors are betting on the wrong technology for the future of AI.

“Currently, the AI hype is centred around frontier models running in data centres with high-end semiconductor equipment and large energy needs.

“Instead, we think that the future of AI lies with small language models (SLMs) running locally on desktops for most tasks. Data centres will be needed to train models and for the most sophisticated and demanding use cases, but not for the vast majority of tasks.”

Panmure added that one of the triggers for the bubble to burst could be that the hyperscalers run out of money for additional capex growth or AI labs run out of capital needed to fund their operations until they become profitable.

The bank said: “Already today, there is much concern about circular financing where Nvidia, Microsoft and others are investing in OpenAI and Anthropic to fund their business.

“These AI labs then commit to renting data centres from hyperscalers running on Nvidia GPUs to train and run their models.

“Once the money stops flowing (either because hyperscalers cut back on their capex to preserve cash or because AI labs cannot raise any more funds), the bubble will likely burst.” 

Your guide to buying Anthropic shares with ii

Whether early investment in Anthropic is available or not to UK retail investors, you will be able to buy shares through ii on the first day they start trading.

Here are the steps you can take in advance to be ready for day 1:

1.    Open an account

You will be able to hold shares in our Trading Account, SIPP, ISA and Junior ISA.

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2.    Complete the exchange agreements

You need to complete this form before you make your first international trade. We will prompt you to complete the agreements the first time you search for an international share price.

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3.    Complete a United States dealing (W-8) form

Before you can buy US-listed shares you need to have completed a W-8 form. You can do this online by logging in and visiting our Useful Forms page. You don’t need to do this if you are only investing in a SIPP.

• Foreign exchange

On the day shares are admitted there will likely be an initial period of price stabilisation, after which trading commences. This may only be a few minutes but can take a few hours.