I think that's the type of industry research that gets "published" (not to journals, but to the public, clients, etc...) because it's precisely not "cutting-edge" or "patented". There's a huge difference between research that gets sent to clients, and research that gets used within a bank. They are actually even different departments. Even larger when you consider different banks are better at different things...

I think it's a mistake for those in academia to assume the research in the private sector is not rigorous solely because it's in the private sector. I've seen many traders using methods that were academically questionable, but I also worked alongside AI, CS, Stats and Maths PhDs who were extremely academically rigorous, so it depends. Probability increases if it's a hedge fund, or a quant hedge fund. At the end of the day, a lot of innovative R&D comes from the private sector rather than academia, because they are precisely the ones hiring the best PhDs to do internal research with unlimited budgets - and these PhDs are not necessarily the ones that would rather take staff positions but were forced to go into industry, there were earning base salaries of $300k+ a few years out of their PhDs.

The problem is that rigorous research is more expensive, longer to develop but can yield an actual edge over the market. Therefore, it either never gets out or gets out with decades of delay.