The stock market seems much more likely to benefit from access to cheap and self-hostable models than it is to suffer from OpenAI/Anthropic losing to competition

Why would it save the stock market? Cheaper models if anything transfers more value to hardware companies and datacentre companies. The two companies that would be most affected are OpenAI and Anthropic, which aren't public.

The two biggest providers deepseek compete with (OpenAI and Anthropic) aren’t in the stock market.