As artificial intelligence companies Anthropic and OpenAI prepare for initial public offerings, Silicon Valley investors are positioning themselves to benefit significantly from the anticipated market debuts. Both companies have attracted substantial funding, with Anthropic raising over $130 billion and OpenAI more than $180 billion from a wide range of investors, including venture capital firms, hedge funds, large technology corporations, and sovereign wealth funds.

Unusually, many investors have backed both startups, despite their status as competitors. Historically, venture capital firms avoided investing in direct rivals, viewing it as a conflict of interest. However, the rapid growth and transformative potential of AI technology have shifted this norm, leading firms such as Sequoia Capital, Founders Fund, Coatue Management, and Altimeter Capital Management to hold stakes in both companies. According to industry insiders, at least 95 investors maintain positions in both Anthropic and OpenAI.

Anthropic, founded about five years ago, initially faced skepticism from traditional venture capitalists, with more than 20 firms reportedly rejecting its early pitches. Instead, early support came from individuals connected to effective altruism, a philanthropic movement emphasizing data-driven social impact. Spark Capital eventually became a lead investor, and its representative Yasmin Razavi joined Anthropic’s board. The company’s leadership, including CEO Dario Amodei, also secured investment from Hollywood talent manager Guy Oseary’s Sound Ventures, which had previously invested in OpenAI. With agreements from the CEOs of both companies, Sound Ventures became one of the first firms to invest in both competitors.

Both startups’ funding needs have outpaced what many venture capital firms can provide individually. To facilitate larger investments, some firms created special purpose vehicles (SPVs) to pool capital from multiple smaller investors. For example, Menlo Ventures established a $750 million vehicle to invest in Anthropic, while Thrive Capital did similarly for OpenAI. Major technology companies such as Google, Amazon, Microsoft, and Nvidia are also significant investors in both startups and have entered into substantial commercial agreements to supply cloud services and hardware.

Anthropic’s valuation was reported at $900 billion after a 2023 funding round, with expectations it could reach $2 trillion at its upcoming IPO, potentially the largest public listing ever. OpenAI is expected to go public next year, also with a substantial market valuation. Despite small percentage ownership shares—typically between 1 and 2 percent—investors are poised for sizable returns given the companies’ scale.

Some firms, like Sequoia Capital, initially declined to invest in Anthropic due to existing commitments to OpenAI and other AI competitors, but later participated in funding rounds as enthusiasm for Anthropic grew. Investors also obtained shares through secondary market transactions and stock conversions resulting from acquisitions made by the AI startups, including Madrona Venture Group acquiring equity in both companies through investments in their acquired firms, Statsig and Vercept.

Both Anthropic and OpenAI have declined to comment on their financial positions or public offering plans. Meanwhile, the AI sector’s rapid evolution and large-scale financing have reshaped investment norms in Silicon Valley, highlighting broad investor confidence in the technology’s transformative potential and the high stakes involved in the companies’ forthcoming market entries.