Microwave Networks (Trading)
Microwave networks in trading are proprietary wireless transmission infrastructures that high-frequency trading firms and financial data providers have built to transmit market data and order signals between major financial center data centers — primarily New York and Chicago — faster than conventional fiber optic cables, exploiting the fact that microwave signals travel through air at speeds closer to the speed of light than signals through glass fiber.
When electronic trading firms discovered in the early 2010s that the round-trip latency between New York and Chicago data centers could be cut from approximately 13 milliseconds via the best available fiber routes to under 9 milliseconds using point-to-point microwave towers, a substantial private investment in wireless trading infrastructure followed. Microwave signals travel through air at approximately 99.97 percent of the speed of light in vacuum, compared to roughly 67 percent for light through glass fiber. On a 700-mile route, this difference compounds to milliseconds of advantage.
Firms including McKay Brothers, Vigilant Global, and Jump Trading built networks of microwave towers along the shortest geographical paths between Chicago Mercantile Exchange data centers in Aurora, Illinois, and New York-area exchange data centers in Mahwah and Carteret, New Jersey. These networks require line-of-sight between towers, meaning they must navigate the topography of the Appalachian foothills and Midwest plains by placing towers on ridges, tall structures, and elevated terrain. Weather conditions, particularly heavy rain and fog, can degrade microwave signal quality, introducing additional latency variability.
The primary commercial application of microwave networks is statistical arbitrage between the CME futures markets in Chicago and the U.S. equity exchanges in New Jersey. When S&P 500 futures move in Chicago, this price signal propagates to equity markets through various transmission paths. A firm with faster transmission can update its equity quotes and trade against stale orders before competitors who receive the Chicago signal via slower fiber connections. This latency arbitrage — buying securities whose prices have not yet updated relative to futures — is a core strategy of many high-frequency market-making operations.
Subsequent to the initial microwave buildout, firms experimented with millimeter-wave and laser-based free-space optical transmission, which offer even lower latency at the cost of greater weather sensitivity. These technologies push the engineering frontier of trading infrastructure and raise ongoing questions about the social value of investments that improve private execution speed by nanoseconds without corresponding improvements in the services delivered to long-term investors.