High-frequency trading — the practice of making thousands of algorithmic stock trades per minute — is about to get a big boost in the USA. Anova, a company that specializes in deploying low-latency networks for stock trading, is completing an ultra-high-speed laser network between the New York Stock Exchange (NYSE) and the NASDAQ. The link will be just a few nanoseconds faster than the current microwave and fiber-optic links — but in the world of high-frequency trading (HFT), those nanoseconds could result in millions of dollars in profits for the trading companies. Such is the insanity of the stock markets; such is the unbelievable capacity of HFT to create money out of almost nothing.
If you want to get a signal quickly from point A to point B, you basically have three options: fiber-optic cables, a network of microwave dishes, or laser links. Electrical (copper wire) networks are feasible over short runs, but their reduced functionality and bandwidth over longer runs makes them less desirable than fiber. Microwave (and even higher-frequency millimeter wave) networks also aren’t very high-bandwidth, but because they’re purpose-built, they can take a very direct route, significantly undercutting the latency of an oft-congested and round-about fiber network.
Laser networks have all the advantages of microwave/millimeter wave networks, but they have higher bandwidth, and some very clever adaptive optics means they’re not impacted by bad weather. (Microwaves really hate inclement weather.)