Since even an old 486 could tax broadband connection speeds, today's monsters are more than capable of responding quick enough.
What's the current system?
My wife's a stock trader and we've had some response time problems with her current system. Testing's been done on our broad band connection and it's fine. So now I'm looking into a "game" type of system that has the best possible graphics, about 1 GB of RAM, fast processor and a fast response monitor (i.e. 4 ms). Does this sound about right and any other suggestions? Believe me, bad response times have equaled loss money......:(