The former, says Richard Posner, in this excerpt from his post:
There is also an echo of the traditional but erroneous suspicion of speculation as an activity that does not create social wealth but merely shifts it around. That is incorrect. Speculation aligns prices (whether commodity prices or the prices of companies) with values and so creates more accurate signals for production and investment. It is a vital economic service. That is not to say that speculators "deserve" higher incomes than ditch diggers. Desert doesn’t enter. Incomes are determined by supply and demand.