When I worked at Scotttrade in 2010, I vividly remember my coworker telling me that this is what they did with the money too. I remember being surprised to hear that it flowed out in the morning and flowed back in in the evening. I never understood why that would make sense till I read your comment here.

It’s all hearsay; I’m just reporting what I heard. I don’t know the implications of it, but maybe this isn’t exactly uncommon behavior, even if it’s market manipulation.

The coworker said that the money flowed overseas too, if that helps contextualize it. No SEC, no problem, right?

Looks like Jane Street is an American firm, so, this all lines up and corroborates what you’re saying. What we’re seeing is probably the first time a government other than the US has reacted to this behavior.