Numeria - Transparency of Rewards Calculations

My latest query around Numerai (Hedge fund backed, distributed AI based decision crypto) is around how are the rewards (for providing better than random trend analysis results) calculated?

I believe it's probably quite complicated compared to Bitcoins mining reward that haves every x blocks (which I think is roughly 4years)

Are the rewards directly or indirectly calculated as a function of returns gained on the hedg fund? Eg 0.001%

Or

Is it something more related to the Numeria ecosystem itself?

Or is it something that's purely managed by the developers?