[netcan]

It is a cost/benefit like anything else. Imagine a market where a position must be held for at least one week.

Sure, there is some efficiency in capital allocation lost but how much of a cost is that really? As I understand it its a loss inasmuch as daily stock price fluctuations reflect the actual underlying of a company: not much.

What do you have on the benefit side? For one thing, you won't have the flood of people betting on whether or not Facebook will "pop."