Anthropic has soared to a $1.2 trillion valuation on secondary markets. Shares are almost impossible to get.

• Since Anthropic has yet to go public, most investors are forced to buy shares via secondary markets.
• The AI company soared to a $1.2 trillion valuation on a popular secondary exchange.
• Even at that high price, getting shares is a Herculean task as almost no one wants to sell.

Anthropic has soared to a $1.2 trillion valuation on secondary markets, but even at that astronomic price, good luck getting shares.

"Anthropic is the most sought-after company the venture secondary market has ever seen," said Javier Avalos, cofounder and CEO of Caplight, a secondary trading platform, where shares are trading at $1.2 trillion.

Glen Anderson, CEO of Rainmaker Securities, a merchant bank focused on private securities transactions, said he is also seeing transactions at $1.2 trillion, though deals remain rare because there are few sellers.

It was less than three months ago that Business Insider reported Anthropic reached a $1 trillion valuation, overtaking OpenAI for the first time. OpenAI, which had been valued much higher for years, is now valued at $908 billion on Caplight.

Anthropic's $1.2 trillion valuation represents a 550% year-over-year increase, according to Avalos.

The company was last valued at $965 billion in a Series H funding round announced in May. Last month, it filed paperwork to go public, with an expected IPO in the next few months.

Since Anthropic and OpenAI have yet to go public, the vast majority of investors are forced to buy via secondary markets, where existing stock is sold by employees or early investors. With the stock soaring, few are willing to part with their shares, and there have been a bevy of shady deals with high fees and byzantine ownership structures. Many have been structured as SPVs, or special-purpose vehicles, which allow investors to pool their funds for a single, one-off deal.

Anthropic declined to comment for this story. On its website, it has lately become more explicit in warning against unauthorized stock sales and scams.

"Invest at your own risk: if someone offers you a way to participate, even on an indirect basis, in an investment in Anthropic, assume that it is invalid," the company warns.

Still, many people have been willing to accept the risks, lest they miss out on what they see as the AI gold rush.

"Most of the supply we have seen in the market has been via SPV structures the company is openly against," Avalos said, adding many of those SPVs come with high fees.

Some interested buyers have gotten more creative, offering to sell their home in exchange for Anthropic shares.

"The demand outstrips the supply in Anthropic so much that it's rare to get a trade done because no one's selling," said Anderson. "If I could close everything I have in Anthropic in terms of demand, I would not be talking to you. I'd be on a beach right now."

Renewed interest in OpenAI

While Anthropic still commands the majority of investor interest—drawing five buyers for every two seeking OpenAI shares—OpenAI has seen a significant surge in momentum in recent weeks.

The enthusiasm is largely driven by the public rollout of OpenAI's powerful GPT-5.6 model series, which includes its new flagship model, "Sol," and the cost-effective "Terra."

"A month ago, we were seeing limited demand for OpenAI," he said. "We're still seeing breakneck demand for Anthropic, but now you're seeing OpenAI get bid on a lot more often."

Martin says he has always tried to follow the company's rules on secondary transactions carefully, but he has become more vigilant lately as Anthropic has intensified its scrutiny. He says he will only participate in "first-layer" SPVs, where the identity of the share seller is known.

"We're trying to make sure the trade is actually there for our investors, versus what could happen, which is Anthropic gets involved in some of these multi-layer SVB trades and invalidates them," he said.

Matt Murphy, a partner at Menlo Ventures, which was an early backer of Anthropic, said he pays little attention to secondary market valuations, calling them a "noisy signal." Nonetheless, he understands the hype, based on the surging revenue numbers Anthropic shared before it entered into an SEC-mandated quiet period ahead of its IPO.

"Those numbers were crazy above what the plan was for the entire year," Murphy said. "So I guess they've earned somewhat the right for there to be quite a bit of interest in investing in the company."