[yummyfajitas]

But regarding Tabarrok's point, I think it's this. It's important for the markets to move much faster than the physical goods they convey information about. I.e., house prices should move much faster than house construction.

Maybe a better analogy is this: there is pirate treasure at GPS coordinates (X,Y). It's good for society if one guy sends a boat to retrieve that treasure. It's less good for society if 5 people get into a race for the treasure. Maybe we get the treasure in 5 days rather than 7, but we also sent 5 boat trips out rather than 1.

Similarly, picking up alpha in 12 seconds rather than 15 is probably not useful to the rest of the world, although picking up alpha is better than leaving it on the table.

I do agree with you that most of the carping about HFT is stupid, however.