6 ms·

Where does this nanosecond number come from for HFT? 1 ns is the time light takes to travel 30 cm in a vacuum. Are these firms only trading with firms that ar

Where does this nanosecond number come from for HFT? 1 ns is the time light takes to travel 30 cm in a vacuum. Are these firms only trading with firms that are a few meters away? How about round trip times? I believe only 10s of microseconds are significant, not nanoseconds.

jonnii 8y ago
That is exactly what is happening in high frequency trading. Firms are paying crazy money to be colocated in the same data centers as the exchanges.
- gcb0 8y ago
  And we as a society know that and think it is normal. Crazy.
  - hazz99 8y ago
    I don't think it's a bad thing - theyre business model relies upon low latency, and so they do everything they can to reduce it
    - gcb0 8y ago
      https://www.smbc-comics.com/comic/trading https://www.smbc-comics.com/comic/trading
- akatechis 8y ago
  Exactly. At an investment bank for which I used to work in NYC, they moved their datacenter to be next door to the exchange's datacenter just to reduce latency. Because in HFT, every fraction of a second can mean the difference between 10s or even 100s of millions of dollars in profit/loss.
analognoise 8y ago
You're right. A 100MHz clock has a period of 10nS. I can tell you exactly how many of them my data path will take (I've only ever used clocks up to about 300MHz in an FPGA - 600 for things like DDR4 memory). What GP means is that the portion of the overall latency which you can control must respond as quickly as possible, and you do count nanoseconds. Obviously HFT has not invented superluminal communication techniques.
- zkms 8y ago
  > Obviously HFT has not invented superluminal communication techniques. They haven't, but they've put in tremendous resources into going above the speed of light in optical fibre, including the use of point-to-point microwave links and, when it's impossible to place towers for microwave links (for example, across the Atlantic Ocean), the use of HF/shortwave (as in 3-30MHz stuff) radio.
  - fileeditview 8y ago
    My question may show my ignorance but how would anyone or anything go above the speed of light? Could you elaborate please?
    - detaro 8y ago
      Speed of light in fibre is lower than speed of light in air, so you can beat fibre speed of light by building fast wireless networks.
      - fileeditview 8y ago
        Thanks. I just looked it up and really wasn't aware of the huge difference.
        diggerNick6771 8y ago
        It's not really the fibre that slows down the signal as much as the opto-electrical repeaters that relay the signal many times as it travels vast distances. Light can only go a few km before it needs to be boosted

jonnii 8y ago

That is exactly what is happening in high frequency trading. Firms are paying crazy money to be colocated in the same data centers as the exchanges.

gcb0 8y ago
And we as a society know that and think it is normal. Crazy.
- hazz99 8y ago
  I don't think it's a bad thing - theyre business model relies upon low latency, and so they do everything they can to reduce it
  - gcb0 8y ago
    https://www.smbc-comics.com/comic/trading https://www.smbc-comics.com/comic/trading
akatechis 8y ago
Exactly. At an investment bank for which I used to work in NYC, they moved their datacenter to be next door to the exchange's datacenter just to reduce latency. Because in HFT, every fraction of a second can mean the difference between 10s or even 100s of millions of dollars in profit/loss.

analognoise 8y ago

You're right. A 100MHz clock has a period of 10nS. I can tell you exactly how many of them my data path will take (I've only ever used clocks up to about 300MHz in an FPGA - 600 for things like DDR4 memory). What GP means is that the portion of the overall latency which you can control must respond as quickly as possible, and you do count nanoseconds. Obviously HFT has not invented superluminal communication techniques.

zkms 8y ago
> Obviously HFT has not invented superluminal communication techniques. They haven't, but they've put in tremendous resources into going above the speed of light in optical fibre, including the use of point-to-point microwave links and, when it's impossible to place towers for microwave links (for example, across the Atlantic Ocean), the use of HF/shortwave (as in 3-30MHz stuff) radio.
- fileeditview 8y ago
  My question may show my ignorance but how would anyone or anything go above the speed of light? Could you elaborate please?
  - detaro 8y ago
    Speed of light in fibre is lower than speed of light in air, so you can beat fibre speed of light by building fast wireless networks.
    - fileeditview 8y ago
      Thanks. I just looked it up and really wasn't aware of the huge difference.
      - diggerNick6771 8y ago
        It's not really the fibre that slows down the signal as much as the opto-electrical repeaters that relay the signal many times as it travels vast distances. Light can only go a few km before it needs to be boosted