That's part of it, but HFT is also a pretty saturated field. It's typically not enough to be fast and physically near the exchange these days; that's a necessar

That's part of it, but HFT is also a pretty saturated field. It's typically not enough to be fast and physically near the exchange these days; that's a necessary but insufficient condition. A lot of nontrivial math and CS is still poured into HFT at places like Two Sigma, Jump and Hudson River Trading.