Several stations licensed in the Experimental Radio Service (ERS) transmit data for automated trading to foreign exchanges in the shortwave or high-frequency (HF, 3-30 MHz) spectrum.
High-Frequency Trading (HFT) is a form of automated trading that employs low-latency, high-speed telecommunications to minimize response times. The term is not related to the shortwave or HF spectrum, but this article concerns transmission of HFT messages on HF frequencies.
HF signals can traverse great distances by refraction from ionized layers of the atmosphere, a phenomenon known as ionospheric propagation. Several ERS HFT stations have operated in the HF bands for years out of the public view. Bob Van Valzah blogged extensively about these stations starting in 2018.
These ERS stations' licenses are public records, but the licensees typically ask the FCC to withhold access to station details and experimental plans. The Commission's routine acceptance of these confidentiality requests makes public oversight difficult.
High Frequency Broadcasting
Two HFT-related ventures, Parable and DPA Mac, have applied for licenses under Part 73F of the FCC rules for the International Broadcast service, also known as High Frequency Broadcasting (HFBC) — not the Experimental Radio Service where HFT stations now operate, ostensibly for research purposes.
A third applicant, Turms Tech, seems to be connected with HFT, but has avoided the topic in its interactions with the FCC.
The potential introduction of HFT in HF broadcasting involves policy questions the FCC has never faced in the more than half-century since the rules for this service were established. The Commission's decisions could radically change the international broadcasting service, by permitting private, nonbroadcast use.