"You can't say a bet is negative value when you don't know the odds" You can. The whole idea of E(V) in trading, gambling, etc, is that V is an unknown distrib

"You can't say a bet is negative value when you don't know the odds" You can. The whole idea of E(V) in trading, gambling, etc, is that V is an unknown distribution, and we're trying to estimate the mean of it using a combination of empirical observation and priors given to us by experience and expertise. Nowhere in this conceptual framework is the idea that we know for sure what the density of V is.