RE: Luminous=absolutely no clue I take comfort in the fact that the shorts seem more focused on the industry than on HCG in particular, i.e. I don't believe most of them have a really good grasp of the HCG business model. There are many better shorts if you think a housing crash is coming (I think prices will go slightly down to sideways for years to come).
That said, its generally not a good idea to assume your opponent is a fool. I've never followed Poseidon (PSN) but after its recent melt down I took a look at the previous guru comments. James Hodgkins was very negative on it while most others were very positive on it, including Jason Donville who said he had a small position in it (I still have great respect for Jason). While Hodgkins returns don't look particularly exciting, I think that's because he's taking a true hedge fund approach designed to remove the market risk.