Long term capital management, although they didnt claim to have the Holy grail, am sure they had a logical argument that they were fully hedged, and they were Nobel prize winners, so what chance do the rest of us have at correctly proving anything?
there is no holy grail because the market is made up of human beings, and NOBODY believes human behavior is predictable with anywhere near 100% accuracy, which would be necessary for a holy grail setup it's that frigging simple