[sithadmin]

I think the gist of what's being argued here is that the increased volume of trades (facilitated by HFT's drive to minimize transaction time) allows more 'real time' information about the relative value of instruments to be communicated.

That said, the first example quoted don't really make a lot of sense, in my opinion. A couple selling off some stock to pay for their child's tuition probably won't ever have their transaction directly represented in the market (it will likely be lumped in with or divvied up from other orders handled by the same brokerage), so the information conveyed is ultimately somewhat diluted.