The secondaries market offers a window into the most-watched-IPO horse race, perhaps ever, between OpenAI and Anthropic.
Now, the vibe, shall we say, for a while has been that OpenAI is falling behind Anthropic. Across the secondaries market, that’s certainly how prospective buyers seem to feel: demand for Anthropic shares is far exceeding the demand for OpenAI shares, pre-IPO market sources have been telling me. And though there’s a sense Anthropic fever has escalated in recent months (including the demand explosion around the company’s mammoth $65 billion fundraise), Anthropic shares have been the most prized for some time.
“Anthropic has been the most in-demand name in the secondary market for about a year,” Javier Avalos, CEO at private markets platform Caplight, wrote to Fortune, adding that he’s seen about $1.5 billion interest in Anthropic since the beginning of Q2 2026.
The demand for Anthropic shares back in May was described to me as “a pressure cooker ready to explode,” and in the aftermath, the company’s running a tight ship when it comes to who it allows to buy its shares on the secondary market.
“In the secondary space, Anthropic really tightened its process around letting people into its cap table,” said Clara Vydyanath, general partner, Underline Capital. “A lot of cap-table GPs have warehoused positions… and they’re now piecemeal-selling blocks worth $20 million, $50 million, $100 million at a time.”
