"If I put $500 on black and $500 on red and the casino gets 5% of the cut, I will eventually lose all my money."
Exactly the point. Clearly no sane investor would play that stategy, but that is exactly what was being done by Opes, so surely it is reasonable to conclude that the investors did not know this was the model that they were investing into. Additionally, your example is about a single person playing both red & black, but the Opes reality was that the investor was playing black (looking for a win) while Opes was using that same investors chips to bet red. A very real distinction.
