4 ms·
Why would they repurpose an old flag at all? That seems crazy to me unless it was something hardware bound.
by solarmist 12y ago
Why would they repurpose an old flag at all? That seems crazy to me unless it was something hardware bound.
- vertex-four 12y agoTo keep the messages as short as possible, to reduce the time-costs of transmitting and processing them. It's HFT, they do things like that.
- jemfinch 12y agoI assume "flag" in this context means something akin to a command-line flag.
- socceroos 12y agoI assumed it was a single bit in a string of them that describes a message.
- MattHeard 12y agoYou're correct. Single bits representing boolean values are often called "flags".
- matteotom 12y agoExcept it's probably a byte or less.
- solarmist 12y agoFor highly efficient messages I'll bet they did bit packing, so it was probably only a single bit, which is why they'd want to reuse it rather than completely change the message format.
- mason240 12y agoWhich is why I don't feel bad at all. Live by the sword, die by the sword.
- otakucode 12y agoI was honestly surprised the NYSE/NASDAQ didn't step in and reverse the trades. They've done so in the past when automated trading systems went off the rails. I am glad they didn't do so, as such favoritism is completely unfair and sends a terrible message to HFT companies, but it was still surprising.
- solarmist 12y agoOkay, I can see that if they're binary messages and a single bit is no longer being used.
- solarmist 12y agoOkay, yeah, if the flag is in the message not just an internal flag that makes MUCH more sense.
- bsdpython 12y agoI've seen it done on a regular basis at a large financial institution. Like, so often that almost half the fields had a different meaning now or have dual purpose on some old systems.