Fable 5 Gets Three Days, Then a Red-Taped Ending: TAO Soars While Traders Short the Hype 🚨

Anthropic suspended access to its Fable 5 and Mythos 5 artificial intelligence models on June 12 after receiving a US government export control directive citing national security concerns, the company said in a statement posted Friday. The directive, received at 5:21 p.m. ET, ordered Anthropic to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees. To ensure compliance, Anthropic disabled both models for its entire customer base, though it confirmed that other models, including Opus 4.8, are not affected.

Fable 5 had been released to the general public on Tuesday, while Mythos 5 had been released only to approved cybersecurity partners. Both are built on top of Mythos Preview, a general-purpose language model Anthropic previously said had found thousands of vulnerabilities in critical software. The government did not provide specific details of the alleged threat, but Anthropic said it believes authorities became aware of a method of bypassing, or "jailbreaking," Fable 5's safeguards. The company reviewed a demonstration of the technique and called it narrow and non-universal, describing it as essentially asking the model to read a specific codebase and fix any software flaws. Anthropic noted that other publicly available models, including OpenAI's GPT-5.5, can discover similar vulnerabilities without requiring any bypass.

Anthropic pushed back on the directive's underlying reasoning, stating that thousands of hours of testing with the US government, the UK AISI, and multiple third-party teams had produced no universal jailbreak. "To date, the government has only given us verbal evidence of a potential narrow, non-universal jailbreak, which essentially consists of asking the model to read a specific codebase and fix any software flaws," the company said. Anthropic warned that applying the standard across the industry "would essentially halt all new model deployments for all frontier model providers." David Sacks, co-chair of the President's Council of Advisers on Science and Technology, wrote on X on Saturday that a trusted partner of both Anthropic and the US government came forward with a jailbreak and that "the admin asked [Anthropic CEO Dario Amodei] to fix the jailbreak or de-deploy the model. Dario refused."

The shutdown rippled into pre-IPO and crypto markets. The Anthropic perpetual contract on Hyperliquid, a cash-settled contract that tracks where traders expect the company's equity to price, fell about 3.7% on Saturday to roughly $1,627, according to data cited in reports. The contract had traded near all-time highs above $1,800 in the days after Fable 5 launched, and open interest sits near $8.6 million. Grayscale head of research Zach Pandl said in a note on Monday that the order shows "the centralized control of frontier AI technology and drives home the need for decentralized alternatives," adding that demand for decentralized AI networks should continue to rise. Bittensor's TAO token climbed roughly 30% in the 12 hours after access was cut, reaching a three-week high of $283 on Monday, according to CoinGecko data cited by Grayscale. Anthropic said it is working to restore access to the models as soon as possible.