Anthropic's pre-IPO market sold off sharply this weekend after the U.S. government ordered the AI safety company to shut down access to its two most powerful models, Fable 5 and Mythos 5, citing national security concerns over a potential jailbreak vulnerability. The company's perpetual contract on Hyperliquid dropped approximately 3.7% on Saturday, falling to around $1,627 from levels near all-time highs above $1,800 that had prevailed in the days following Fable 5's launch.

Market Context

The shutdown directive arrives as Anthropic was positioning itself for a potential public listing, with its pre-IPO equity trading on Hyperliquid's perpetual futures market. The contract, which allows traders to speculate on where Anthropic's shares might price in an eventual IPO or direct listing, had attracted meaningful open interest of approximately $8.6 million—small relative to contracts tracking more established private companies like SpaceX but significant for a company that has not yet filed for a public offering. The broader AI sector has seen heightened investor interest following the successful launches of competing frontier models from OpenAI and Google DeepMind.

Analysis

The government's order, received by Anthropic at 5:21 p.m. ET on Friday, cited national security authorities and initially required suspension of all access to Fable 5 and Mythos 5 for foreign nationals inside or outside the United States before evolving into a full customer shutdown. Anthropic immediately complied but pushed back hard on the directive, arguing that Washington has provided only verbal evidence of what the company describes as a narrow, previously known vulnerability. The technique in question reportedly involves asking the model to read a codebase and fix software flaws—a task that defenders use daily, according to Anthropic's statement.

The San Francisco-based company's challenge is notable given its brand identity as a safety-first AI developer. Anthropic argued that applying this standard across the industry would 'essentially halt all new model deployments for all frontier model providers.' The company also pointed out that other publicly available models, including OpenAI's GPT-5.5, can identify the same vulnerabilities without any bypass at all—suggesting the finding may not represent a unique security gap specific to Anthropic's architecture.

The crypto market's negative reaction reflects concerns about regulatory risk as a potential IPO overhang. Traders are now watching for whether Washington reverses, narrows, or extends the directive once Anthropic publishes its technical rebuttal within 24 hours. The incident raises questions about how federal authorities will handle oversight of increasingly powerful AI systems ahead of anticipated public market debuts in the sector.

Key Numbers

- 3.7% decline in Anthropic perpetual on Hyperliquid, falling to approximately $1,627

- All-time high trading levels above $1,800 reached shortly after Fable 5 launch

- $8.6 million open interest on the Anthropic perpetual contract

- 24-hour window for Anthropic to publish details about the specific jailbreak technique

What to Watch

Anthropic's technical rebuttal and the government's response will be critical near-term catalysts. Traders should monitor whether Washington narrows or reverses the shutdown order, extends similar directives to competing frontier model providers like OpenAI and Google DeepMind, or releases documented evidence of the alleged vulnerability beyond verbal briefings. The company's IPO timeline and pre-IPO share price trajectory on Hyperliquid will hinge on how this regulatory dispute resolves.