I've seen a number of claims that it's 10T or 6T paramètres and MoE, but without sources. Simon Willison has some good points about why it certainly feels big: simonwillison.net/2026/Jun/9/c...
Who's Who of AI
Jelle Zuidema 🟥
Associate Professor of Natural Language Processing & Explainable AI, University of Amsterdam, ILLC
What they're sharing
Initial impressions of Claude Fable 5 simonwillison.net
Articles & links
Their own posts
Recent commentary
Does anyone know of some plausible speculations on *technical innovations* driving the impressive performance of Mythos/Fable? The model card only talks about evaluations (interestingly, mostly in biology). The interpretability work on Mythos Preview suggests it's essentially all based on versions
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