Is the kind of HFT that Jane Street does that reliant on extremely low latency? A lot of HFT firms operate on the timescale of seconds, minutes, or even hours, not milliseconds.
I feel like there must be terminology confusion here - the HF in HFT stands for high frequency, which effectively means low latency. There may be HFT firms that additionally do slower stuff, but no one would call a trade on the timescale of hours HFT - it's a fuzzy line, but certainly nothing measured in units larger than microseconds would qualify to someone in the industry, and the line is likely lower than that.
