Off topic, but I just received this email today.



Here's maybe a relevant but old article. https://www.zerohedge.com/article/citadel-set-control-975-e-trades-order-flow

As for brokers recommendations have a dig here: https://nexusfi.com/reviews-brokers-data-feeds/

Thanks @JustinIsHere, I moved this to it's own thread.

Mike