alt Hacker NewsThat'd be quite a challenge!
From a quick Google I see that HFT carries out trades in an average of 700ns, which is close to the cycle time of a 150kHz carrier, so you'd have to come up with some really clever phase modulation scheme that could carry meaningful data in *one single cycle*.
You're definitely going down the SDR route for that.
It's still technically "high frequency", just in terms of sound rather than trade volume. Also if it's some cryptobro's pet project it probably needs time to settle on some blockchain ledger, so extra reason to find a new meaning for "high frequency" like sound wave cycle to confuse the marketing on the project.