Anthropic unveiled upgraded Fable 5.2 and Mythos 5.2 AI models with enhanced capabilities, lower costs and tighter safety testing ahead of its anticipated IPO. | Business. The new models, Fable 5.2 and Mythos 5.2, can perform up to 30 percent faster than previous versions, particularly for complex tasks like coding, while costing 20 percent less, the company said.