Anthropic has soared to a $1.2 trillion valuation on secondary markets, but nobody wants to sell. With Anthropic yet to go public, most investors hunt for shares on the secondary market, buying from employees and early backers. Anthropic has been explicit: if someone offers a way to invest indirectly, "assume that it is invalid." Still, plenty of investors are willing to chance it. BI's Ben Bergman found a private market resembling a modern-day gold rush. While Anthropic remains the hottest ticket, OpenAI is quietly making a comeback ahead of the public rollout of its most advanced AI model.