No. NY4 is in Secaucus. NYSE operates out of an ICE (NYSE parent co) owned facility in Mahwah about 25 miles north of there. They managed to pick out the one big US equities exchange operator _not_ running in an equinix facility.

Sorry but this whole post sounds like someone who is sort of HFT adjacent but doesn't really know what they are talking about. Sending orders at "09:29:59.9999971 at the hope your order arrives at 100ns past 9.30am." What?

This, to me, is the most important question. There is no way Andres Freund just happened to find the _only_ backdoored popular open source project out there. There must be like a dozen of these things in the wild?

Retail orders are small and generally aren't capable of moving prices. Your order for 100 shares of whatever isn't going to move the price so you can't really make money ahead of it.

I suspect that AFOP was probably a typical low volume small cap and that Li’s selling while not large in nominal terms was probably still pretty significant relative to the average daily traded volume. Large enough to be picked up by a pretty simple screen anyway.

The underlying index was up something like 90%. So VXX up 90% and XIV down 90%. Next day the index goes down 25% so VXX down 25% XIV up 25%. The two day returns for VXX will be 1.90 * .75 = 42% up and the two day returns for XIV will be 0.10 * 1.25 = 87.5% down. You can see how the daily tracking blows out the tracking over longer terms (just 2 days in this case). Since the VIX moves had been relatively small on a day to day basis, it sort of looked like they tracked each other on inverse terms over longer periods but it was just an illusion.