[sillysaurus3]

It's 1ft/ns in a vacuum, but my understanding is that it's closer to 0.5ft/ns in a wire, so what you say is doubly true. But I think HFTs are running on servers close to the NASDAQ datacenter, and that people pay buckets of money for such privileges.

[TrainedMonkey]

Pretty sure NASDAQ rents servers directly on site for serious dough, so distance is not that much of an issue.

[kasey_junk]

Yes and No. Nearly every electronic exchange now offers co-location services (including NASDAQ).

The "serious dough" part is a little harder to quantify. I've not looked into NASDAQ specifically but server colocation is usually on the order of a couple of thousand dollars a month. This is a drop in the bucket compared to the real costs of a professional trading outfit (namely employees and margin/risk costs).

Anecdotally, it's also almost exactly what I paid for a tier 1 co-located server at my first job in a startup during the first dotcom boom.

[steven2012]

Wire? It's infiniband and other bufferless network protocols over fiber.

[jagger27]

Fiber is still only about 66% of c.