Anthropic is reportedly thinking much bigger than a normal tech IPO. Bloomberg reported that the Claude developer expects its planned public offering to match or exceed the $75 billion SpaceX raised in its June debut, which was the largest U.S. IPO on record. Anthropic could make its public filing as soon as the end of August, although the size, timing, and valuation are still subject to change.
The valuation may ultimately matter more to investors than the amount raised. A company can sell a relatively small percentage of itself and still bring in tens of billions of dollars. Anthropic has not publicly set a valuation for the IPO, and that number could have ripple effects well beyond the company itself. Amazon and Microsoft both hold Anthropic investments, and both have already reported sizable accounting gains tied to those stakes.
The Valuation Matters More Than the $75 Billion Headline
SpaceX sold 555.6 million shares at $135 apiece in June, raising just under $75 billion before the underwriters’ additional-share option. Anthropic matching that number would be remarkable, but it would not tell investors what the company is actually worth. That depends on the IPO price, the number of shares outstanding, and how much of the company is being sold. Until Anthropic files publicly, investors do not have those numbers.
That is why the valuation is the part worth watching. A strong public-market price for Anthropic could become a fresh reference point for other private AI companies and for public companies carrying large AI investments on their balance sheets. It could also influence expectations for a future OpenAI offering. But it would be too aggressive to assume one IPO automatically resets every AI stock. Public companies still have to be valued on their own revenue, profits, cash flow, and exposure to the AI spending cycle.
Amazon Has the Most Direct Anthropic Exposure
Amazon (NASDAQ:AMZN) is the clearer public-market Anthropic play. Its second-quarter results included $53.4 billion in non-operating pre-tax other income, which Amazon said came primarily from its Anthropic investments. That helped push quarterly net income to $62.6 billion, or $5.75 per diluted share. The distinction matters for investors: this was largely an investment-related accounting gain, not $53.4 billion of new profit generated by Amazon’s retail or cloud operations.
The relationship also goes far beyond a passive investment. AWS remains Anthropic’s primary cloud provider and training partner, and Amazon said both Anthropic and OpenAI have made multi-year, multi-gigawatt commitments to its Trainium chips. AWS revenue reached $42.2 billion in Q2, up 36.7% from a year earlier and its fastest growth in 18 quarters. Amazon also invested another $5 billion in Anthropic preferred stock during Q2. A successful IPO could provide a new observable valuation point for that investment, although the accounting impact would depend on the securities involved and the final transaction.
Microsoft’s Anthropic Stake Is Smaller, but It Still Matters
Microsoft (NASDAQ:MSFT) also has direct Anthropic exposure, although OpenAI remains the much larger strategic relationship. Microsoft agreed in 2025 to invest up to $5 billion in Anthropic, and its fiscal fourth-quarter 2026 results included a $3.2 billion gain from that investment. Microsoft’s current annual filing, meanwhile, says its OpenAI investment represented approximately a 25% interest on an as-converted basis as of June 30.
That makes Anthropic’s IPO useful in two ways for Microsoft shareholders. First, it could create a clearer market reference for Microsoft’s Anthropic holding. Second, it gives investors another public benchmark for valuing frontier AI businesses before OpenAI eventually reaches the market. Microsoft is also less dependent on any single model provider than the original framing suggested. Its Foundry platform offers more than 11,000 models, including models from Anthropic, OpenAI, Mistral, xAI, and others.
What Investors Should Look for in Anthropic’s Filing
The headline valuation will get most of the attention, but the filing underneath it will matter more for long-term investors. Revenue growth is only part of the equation for an AI company spending heavily on chips, data centers, and cloud capacity. Investors should look closely at Anthropic’s operating margins, cash burn, compute commitments, customer concentration, debt, and how much of the IPO consists of new shares versus existing shareholders selling stock.
That distinction is especially important for investors approaching or already in retirement. Amazon or Microsoft can be major holdings even for people who never bought either stock directly, because both sit near the top of many broad market and technology funds. Anthropic’s IPO could affect how Wall Street values parts of those businesses, but a higher private-company valuation is not a substitute for recurring earnings or cash flow. The real question is whether Anthropic’s eventual public numbers can justify the price investors are being asked to pay.