An intrepid researcher has mapped some of the microwave towers being used to conduct high-frequency-trading around the world.

HFT requires competitors to use cutting-edge technology to see ahead. It has antecedents:

Height, then, played an important part in facilitating that speed. A trader’s physical height became an advantage, which is part of the reason some traders were former basketball or football players –“taller traders were easier to see”. In the 1990s, some traders wore high heels in the pits to trade faster, and inevitably experienced injuries due to lack of balance. This prompted the Chicago Mercantile Exchange (CME) to impose a ruling making the maximum size of platform heels two inches in November 2000.

via Alexis Madrigal.

Speaking of antecedents, one of the cons lovingly illustrated in the 1990 movie The Grifters involves exploiting time delays to make money on financial markets. The con involved selling the promise of that grift, not actually carrying it out. Brilliant.