Trading firms are asking FCC to open shortwave frequencies to greater commercial use Ham radio operators are sounding the alarm over the latest threat to their beloved hobby—and this time, it is coming from Wall Street. A group of high-frequency trading firms is asking the Federal Communications Commission to open shortwave frequencies to greater commercial use, so they can use radio to zip financial data around the world in milliseconds. Prominent members of the amateur-radio community say interference from traders’ broadcasts could ruin their hobby, which often involves tuning in to weak radio signals so they can chat with fellow...