Gambling is a useful analogy but what is missing is that a person creating a business or buying a house, fixing it up, and flipping it are taking a risk on /profit/ but fully intend on creating real value whether they end up losing money or not.

That's quite a bit different than laying a bunch of money on red at a roulette table. The only value created -- the fun of the gamble itself -- is completely intangible and immediately destroyed.

Of course, there's a spectrum there, too. How much value is created by the efficient allocation of capital in our markets? Lots, it can be easily argued. Well, what about the marginal micro-transactional allocation in HFT? Well, maybe not so much.