7 ms·

I love how it's just some dude running a delivery truck inadvertently doing this. It's like something out of a movie.

wmf 13y ago
Yeah, I was hoping it was the ten minutes before market close every day and some evil genius HFT operator was trying to exploit lack of time sync at the exchange.
- joosters 13y ago
  Same here. If they were really cunning, they could fabricate their own signal with a different timestamp. You could shut down rivals by making their computers believe that the trading day was over, or that their market feed was too slow to trust...
  - nonchalance 13y ago
    You could do that over very small timeframes (say, a millisecond earlier or later) but most systems don't automatically adjust times if the delta is very large
    - dllthomas 13y ago
      A millisecond is a long time.
      - maurycy 13y ago
        You can make a million dollars in a millisecond.
        dllthomas 13y ago
        I wasn't being sarcastic.
      - nonchalance 13y ago
        For regulatory purposes, milliseconds are negligible. FINRA allows for up to 3 seconds of divergence from standard time sources. For deep alpha signals, a millisecond is pretty negligible (especially when you are calculating minute or 10 minute bars). For microstructure trading strategies, since the timing doesn't manipulate the book (which is where most microstructure trades derive alpha from), the effect is similarly negligible. And for cross-exchange and cross-asset arbitrage, where microseconds may seem matter (regnms), slight drifts are permissible insofar as you can plausibly argue that even if the clock is slightly off, your view of the market is internally consistent
        dllthomas 13y ago
        Shift of the clock signal by milliseconds may well not matter, for sure, assuming all relevant clocks are affected.
  - jrockway 13y ago
    Most people are using GPS-disciplined oscillators, not raw GPS clocks, so don't need GPS coverage except for very long-term stability. The crystal in the oven stays plenty stable over the timeframe of hours and days, and takes priority over any shady-seeming GPS updates. The worst you can do is cause a loss of a few ppm clock stability. (These are only $200 on eBay and I have one at home. From time to time I have a bad GPS signal and my consumer-grade ntpd marks the GPS clock as a "false ticker" and falls back to the PPS signal only.)
rmc 13y ago
It sorta drives home how vulnerable the systems are. If someone can do it accidentally, the what could a malicious, well resourced attacker do? How come a well resourced attacker hasn't done it?
- zokier 13y ago
  > How come a well resourced attacker hasn't done it? Umm.. the article mentions that NK has been jamming GPS, and Iran allegedly landed US drone via GPS hacking. Well resourced attackers are doing it.
speeder 13y ago
There is a legendary tale of a how a random delivery truck took down a whole popular MMO. The MMO company had a issue with their own physical logistics, and had to put their login server across the street in another building. They put special antennas between the two buildings, to keep the thing running, and it worked great, until one day, it didn't. After a while trying to figure what was going on, they noticed that a huge delivery truck parked illegally (the place where it parked was illegal to anyone park), and the place he choose made the bulk of the truck metal stay right between the two antennas... EDIT: Also when internet was still dial-up, one delivery truck ignoring height limits managed to cut all phone cables near my town biggest ISP, leaving the entire city without internet. I did not appreciated it...
- DrStalker 13y ago
  I've heard of a similar issue with a wireless data link across a river that would cut out once or twice a day, but not everyday, and no one could figure out why. The answer only came after a few weeks of monitoring and an ametuer fisherman saying "hey, those are all high tide times!" at which point they realise that high tide was causing the mast of a docked boat to rise up enough to interfere, and that the boat was not always in its dock which is why some days were fine.
  - jlgaddis 13y ago
    This is typically off-topic but you found that case interesting you might also enjoy reading "The case of the 500-mile e-mail": http://www.ibiblio.org/harris/500milemail.html http://www.ibiblio.org/harris/500milemail.html

wmf 13y ago

Yeah, I was hoping it was the ten minutes before market close every day and some evil genius HFT operator was trying to exploit lack of time sync at the exchange.

joosters 13y ago
Same here. If they were really cunning, they could fabricate their own signal with a different timestamp. You could shut down rivals by making their computers believe that the trading day was over, or that their market feed was too slow to trust...
- nonchalance 13y ago
  You could do that over very small timeframes (say, a millisecond earlier or later) but most systems don't automatically adjust times if the delta is very large
  - dllthomas 13y ago
    A millisecond is a long time.
    - maurycy 13y ago
      You can make a million dollars in a millisecond.
      - dllthomas 13y ago
        I wasn't being sarcastic.
    - nonchalance 13y ago
      For regulatory purposes, milliseconds are negligible. FINRA allows for up to 3 seconds of divergence from standard time sources. For deep alpha signals, a millisecond is pretty negligible (especially when you are calculating minute or 10 minute bars). For microstructure trading strategies, since the timing doesn't manipulate the book (which is where most microstructure trades derive alpha from), the effect is similarly negligible. And for cross-exchange and cross-asset arbitrage, where microseconds may seem matter (regnms), slight drifts are permissible insofar as you can plausibly argue that even if the clock is slightly off, your view of the market is internally consistent
      - dllthomas 13y ago
        Shift of the clock signal by milliseconds may well not matter, for sure, assuming all relevant clocks are affected.
- jrockway 13y ago
  Most people are using GPS-disciplined oscillators, not raw GPS clocks, so don't need GPS coverage except for very long-term stability. The crystal in the oven stays plenty stable over the timeframe of hours and days, and takes priority over any shady-seeming GPS updates. The worst you can do is cause a loss of a few ppm clock stability. (These are only $200 on eBay and I have one at home. From time to time I have a bad GPS signal and my consumer-grade ntpd marks the GPS clock as a "false ticker" and falls back to the PPS signal only.)

rmc 13y ago

It sorta drives home how vulnerable the systems are. If someone can do it accidentally, the what could a malicious, well resourced attacker do? How come a well resourced attacker hasn't done it?

zokier 13y ago
> How come a well resourced attacker hasn't done it? Umm.. the article mentions that NK has been jamming GPS, and Iran allegedly landed US drone via GPS hacking. Well resourced attackers are doing it.

speeder 13y ago

There is a legendary tale of a how a random delivery truck took down a whole popular MMO. The MMO company had a issue with their own physical logistics, and had to put their login server across the street in another building. They put special antennas between the two buildings, to keep the thing running, and it worked great, until one day, it didn't. After a while trying to figure what was going on, they noticed that a huge delivery truck parked illegally (the place where it parked was illegal to anyone park), and the place he choose made the bulk of the truck metal stay right between the two antennas... EDIT: Also when internet was still dial-up, one delivery truck ignoring height limits managed to cut all phone cables near my town biggest ISP, leaving the entire city without internet. I did not appreciated it...

DrStalker 13y ago
I've heard of a similar issue with a wireless data link across a river that would cut out once or twice a day, but not everyday, and no one could figure out why. The answer only came after a few weeks of monitoring and an ametuer fisherman saying "hey, those are all high tide times!" at which point they realise that high tide was causing the mast of a docked boat to rise up enough to interfere, and that the boat was not always in its dock which is why some days were fine.
- jlgaddis 13y ago
  This is typically off-topic but you found that case interesting you might also enjoy reading "The case of the 500-mile e-mail": http://www.ibiblio.org/harris/500milemail.html http://www.ibiblio.org/harris/500milemail.html