I've seen various claims to this (eg [1][2][3]) but nobody reall knows. These may all come from one uunsubstantiated claim. It is I think widely accepted that Mythos is ~10T parameters.

I've seen figures that suggest GPT-4 was 1.8T parameters and cost upwards of $100 million to train (also unsubstantiated), in which case the Mythos figure might be inflated and also include development costs.

So who really knows?

[1]: https://www.softwarereviews.com/research/claude-mythos-previ...

[2]: https://x.com/duttasomrattwt/status/2041903600516133016

[3]: https://www.forrester.com/blogs/project-glasswing-the-10-con...