This article gives some good insights into high-frequency trading environments and the cyber security threats they face, although -- as with many articles like this -- it tends to portray cyber threats in tones that are a bit too cloak-and-dagger for my taste.
The short version is that these low-latency high-frequency trading environments . . .
1. Are very important, especially because of the amount of money that traverses them every second of the day.
2. Aren't much regulated.
3. Aren't nearly as well understood as traditional networks from a security perspective.
4. Are going to get more important, not less.
If you want to know more about the issue, I also recommend a blog post by a colleague of mine, which talks about both her experience in testing low-latency network equipment and the broader challenges faced by operators of these networks:The Elephants in the Room: Meeting the Challenges of Low Latency and High Volume for Financial Exchangeshttp://is.gd/xtd5IO
If you want to know more about this (with or without any interest in my company's wares), please do let me know.
[Note: These are my views, not my employer's.]