Very little is actually known about what RenTec is doing. They claim to use "the simplest tools in a smart way" in interviews, with linear regression/prediction being the most useful - but I take that to be disinformation.

No one who has a working predictive model for the market will disclose it - doing that guarantees they will stop making money shortly. But making any money consistently means you have a useful prediction of the future, even if those are not the terms you use to describe it. Cover & Thomas ("Elements of Information Theory") has a chapter or two proving the equivalence between being able to profit and having "more information about the future" than other market participants, in a well defined, quantified way.