US Export Controls Force Anthropic to Disable Fable 5

The U.S. Commerce Department issued an export-control directive on June 12, 2026, requiring Anthropic to suspend access to its most capable models, Claude Fable 5 and Mythos 5, for all users worldwide.

Anthropic released Claude Fable 5 on June 9 as a top-tier model in its Mythos class. The model included real-time safety classifiers that routed some flagged queries to an older model, Claude Opus 4.8, instead of completing them with Fable 5. The classifiers targeted cybersecurity prompts with offensive potential, biology and chemistry queries with dual-use risks, and attempts to extract model capabilities for use in training competing systems. The company reported the triggers affected fewer than 5% of sessions on average, though some users said benign prompts were flagged.

After adjusting some restrictions, Anthropic disabled Fable 5 and Mythos 5 on the evening of June 12. The Commerce Department’s directive required suspension of access for foreign nationals, including foreign-national employees both inside and outside the United States. Anthropic explained it could not reliably segment users by nationality in real time and opted for a global shutdown to comply. Earlier models such as Claude Opus 4.8 remain available. Anthropic has stated it is working to restore access but has given no timeline.

The directive cited national security concerns tied to the models’ advanced capabilities in cybersecurity and biology.

Secondary markets that track Anthropic’s implied private valuation moved lower after the shutdown. On Hyperliquid, the synthetic perpetual futures contract vntl:ANTHROPIC fell about 3% to roughly $1,638, a price that corresponds to an implied Anthropic valuation near $1.638 trillion. Open interest on the contract was about $8.66 million, 24-hour trading volume near $191,000 and the funding rate 0.0056%. On Solana, the Prestocks ANTHROPIC token declined 9.11% in 24 hours to about $655.32 and traded at a roughly 29.87% discount to its mark price of $934.48. Net selling volume over 24 hours reached negative $92,500 across 702 active traders. Liquidity in associated pools fell about 18.09% to $126,000 and the token’s holder count dropped to roughly 4,630 wallets; by 9:30 a.m. EDT on June 13 the token was quoted at $659.59.

Both trading products carry warnings. The Hyperliquid perpetual is a synthetic derivative with no special-purpose vehicle backing and carries liquidation risk at leverage up to three times. The Prestocks token claims 1:1 SPV backing, but Anthropic has warned that unauthorized tokenized or derivative products claiming exposure to its equity may be considered void. Neither product is affiliated with Anthropic. The company previously filed confidentially for an IPO at a reported valuation between $965 billion and $969 billion.