i don't see much of a difference in philosophies or methodologies between the two... a good gambler or odds maker (sports book) will take all info, use a model and calculate odds... if the risk reward payoff is worth it, the gambler will take the bet or offer the bet out. A trader does the same thing, the only difference between the two is that there are larger barriers to entry into trading. the pool of traders on average are better at making money than the pool of gamblers, but if you take the best in Vegas vs. the best on Wall Street I don't think you'll see much of a difference in relative P&L.poker is a great example. Lets say a guy betting the nut hand with the "river" left to come is making a risk reward bet based on the fact that there are 10 cards that could drop making his hand second best. the next player to call is left with a decision. is the total value of the pot worth calling the bet based on the odds of the card dropping. But then there are other factors in play, such as human behaviour (is he bluffing), and imperfect information (do i really have 10 outs or are bunch of those outs already mucked). all these variables are apparent in the every day life of a trader. the real difference between the two is that one is considered a career which companies will provide salaries for, the other isn't.