Anthropic, the company behind the popular AI assistant Claude, has taken a major step toward going public. The company has filed its IPO paperwork with US regulators, according to Reuters, and the numbers being discussed are staggering: the company could try to raise as much as $100 billion in what would be one of the largest stock market debuts ever attempted.
For everyday investors, this is more than just another tech IPO. It's a test of how much the public markets are willing to pay for artificial intelligence companies that are growing fast but spending heavily to stay ahead. The outcome could influence how money flows into and out of AI stocks for years.
What we know about the filing
Making the filing public is a key procedural step before Anthropic can begin its IPO roadshow, where company executives pitch the stock to institutional investors. Reuters notes that an earlier timeline had slipped, so this filing signals the process is moving forward again.
The valuations being discussed are eye-popping. Reuters reports that Anthropic raised funding at a post-money valuation of $965 billion in late May. That means investors valued the entire company at nearly $1 trillion just a few months ago. Now, some investors are reportedly talking about a valuation around $1.5 trillion, especially after a recent investor event raised expectations.
If Anthropic really pursues a raise of up to $100 billion, it would rank among the largest IPOs ever. For context, that's more than the total market value of many well-known companies. Deals of this size can have ripple effects across the entire stock market.
A wave of AI listings
Anthropic isn't the only AI giant heading to the public markets. Reuters has reported that OpenAI, the maker of ChatGPT, has also filed confidentially and has been sounding out investors at valuations above $1 trillion. Together, these two companies represent the most prominent names in the current wave of AI listings.
This wave is happening at a time when investors are already wrestling with a big question: will the enormous spending on AI infrastructure and research eventually pay off? AI's ballooning costs have pushed some investors toward safer government bonds, as they weigh the risks of betting on companies that are burning through cash to build out their models.
Both Anthropic and OpenAI are pursuing what analysts call a "scale-first" strategy: spend heavily on computing power, data, and talent to build the most capable AI models, with the hope that market dominance will eventually translate into huge profits. The public markets will now have to decide whether that bet is worth it.
What a mega-IPO means for your portfolio
If Reuters is right that Anthropic could seek up to $100 billion, the early market impact may be less about day-one excitement and more about basic portfolio mechanics. When a new company is large enough to matter for major indexes, benchmark-aware funds and "closet index" managers (active funds that stay close to an index) often need to make room for it. That can mean trimming existing large holdings to free up cash, even if nothing changed about those businesses.
So a mega IPO can create short-lived cross-currents: more turnover, bigger swings between winners and losers, and unusual pressure in parts of the US large-cap market as portfolios rebalance around the new weight.
For individual investors, the key takeaway is to understand that a listing this size can affect the broader market, not just the company itself. If you own index funds or ETFs, you could see some temporary volatility as funds adjust. If you own individual stocks, you might notice that some of your holdings get sold off as fund managers make room for the new arrival.
It's also worth remembering that IPOs are risky. Companies in this position often have high growth but also high costs and uncertain paths to profitability. The hype around AI can push valuations to levels that may not be justified by current earnings. Anthropic's IPO plans put AI spending back in focus as the Fed and tech earnings loom, adding another layer of uncertainty.
What to watch next
Investors will be watching several things in the coming weeks. First, the exact size and valuation of the IPO when it's priced. Second, how other AI stocks react—if Anthropic gets a huge valuation, it could lift the whole sector, but if it struggles, it could drag down sentiment. Third, the broader market environment, especially interest rates and the health of the economy. Big Tech earnings and the Fed's next decision will both play a role in setting the tone for risk-taking.
For now, the filing is a reminder that the AI boom is entering a new phase. The private markets have been generous to AI startups, but the public markets are a different beast. Whether Anthropic can pull off a $100 billion IPO will be a defining moment for the entire sector.
