The traditional notion of investor loyalty in venture capital is unraveling, especially in the high-stakes world of AI. As OpenAI nears a $100 billion funding round and Anthropic just closed a $30 billion raise, at least a dozen venture capital firms that back OpenAI are now also investing in Anthropic. Among them are prominent names like Founders Fund, Iconiq Capital, Insight Partners, and Sequoia Capital—firms long seen as aligned with a single startup’s mission. This shift is particularly striking because venture capital has historically operated on principles of exclusivity and deep alignment with portfolio companies. VCs market themselves as founder-friendly, offering not just capital but strategic guidance and access. The expectation has been that investors would support their startup’s growth and competitive edge—especially against rivals. But now, with AI labs raising unprecedented sums to build infrastructure and train models, the lines are blurring. Some dual investments make sense in the context of asset managers and hedge funds, which often hold diversified portfolios across competitors. Firms like D1, Fidelity, and TPG fall into this category, where investment decisions are driven by broad market exposure rather than startup-specific loyalty. Even more surprising is that affiliated funds of BlackRock participated in Anthropic’s round, despite senior BlackRock executive Adebayo Ogunlesi serving on OpenAI’s board. Given BlackRock’s vast range of funds—mutuals, ETFs, closed-ends—it’s not uncommon for different arms to invest independently, even in competing ventures. The situation is further complicated by the fact that OpenAI and Microsoft have a deep, intertwined relationship. Microsoft’s investments in OpenAI are well known, yet it has also backed other AI players, including Anthropic. Similarly, Nvidia, while a key enabler of AI compute, has stakes in multiple AI startups. Yet for venture capital firms, the departure from loyalty is more jarring. Traditionally, VCs avoid backing direct competitors to protect fiduciary duties and maintain trust. But now, the scale of opportunity is overwhelming. With AI labs requiring massive capital for data centers, chips, and talent, the stakes are too high to pass up. As one investor put it, as long as a firm isn’t on a board, they see no conflict. Sam Altman, OpenAI’s CEO and a former Y Combinator president, was once reported to have asked investors not to back certain rivals—especially those founded by former OpenAI employees like Anthropic, xAI, and Safe Superintelligence. While he later denied issuing a formal ban, internal documents from the Elon Musk lawsuit revealed he warned that non-passive investors would lose access to confidential information. That’s a clear signal of the tension. Still, not all VCs have crossed the line. Andreessen Horowitz, Menlo Ventures, Bessemer Venture Partners, General Catalyst, and Greenoaks are among those who appear to back only one of the two companies. However, the fact that major players like Sequoia and Insight are now investing in both suggests a new normal. As AI continues to redefine the rules of capital, founders must now consider conflict-of-interest policies more carefully during term sheet negotiations. The era of investor loyalty may be over—replaced by a new calculus where the size of the prize outweighs the cost of divided allegiance.