People who think they have a secret alpha-generating system that they never backtested are idiots. Even if you have something that has potential, it’s no different from stuff that you can already find online. And if someone wants to spend months or years improving something then they have a million of systems to choose from.
I guess I am an idiot then, as I have something that my competitors do not have and it actually generates alpha in real life. Same goes for PDT, the ETL team, RenTech and many other successful funds or PMs. There are infinite dimensions to alpha generation and ability to come up with new strategies comes down to a combination of creativity, knowledge of the market and the skillset to actually trade it. It's a pretty rare skillset, believe it or not.
Try googling and you not gonna find anything about real life intraday statistical arbitrage, high frequency trading or alternative data strategies. For that matter, pretty much anything that is being currently used in the industry is not in the public domain.
People who do develop good ways to extract alpha guard their secrets in all ways possible. For example, 1-year non-compete clauses are standard and I am hearing of 2-year non-competes more and more. People who tried copying strategies or even benign bits of code have gone to jail. So there are a lot of real secrets out there and no, you can't find everything online.
While the guy who actually made more money then everyone here combined, Sarao, is the one who hired a programmer. Was he such an idiot?
Most PMs/fund teams have multiple people, that's the only way to gain leverage. There are two possible approaches to alpha leakage in these cases. One approach is to build a cohesive team that is very loyal to each other and sticks together. While there is usually a clear leader, the team shares everything and trusts each other explicitly. It's a highly collaborative approach that yields the best results, in my experience - in fact, all successful teams I've seen where built on that approach. An obvious drawback is that hiring new people is very hard, as your choices are very important.
Others have instead built a highly compartmentalized process where their employees have only partial knowledge of what's going on. In this case, programmers and quants are replaceable and there is relatively little risk in them leaving. Of course, this makes for a very inefficient process where no single employee has a big picture view.
In Navs case, he has been with that programmer for years from what I understand and was sharing a lot of information with him. While it was working well, ultimately this was also his downfall - the email exchanges was the key evidence in his trial.
I read your message as "everything is out there in public domain, its not worth doing original research and there is no such thing as secret alpha". Mea culpa.