Comment by dist-epoch

Not Citadel, but Jane Street is training LLMs for trading:

https://www.janestreet.com/join-jane-street/machine-learning...

> We build on the latest papers in LLMs, computer vision, RL, training libraries, cuda kernels, or whatever else we need to train good models.

> We invent our own set of architectures and optimizations that work for trading.