100% agree, you could see the buy side changing 5000 at a time...

100% agree, you could see the buy side changing 5000 at a time 4-4:10pm. At each 5000 drop the match price would change to reflect the bids and the bot would obviously check to see if the match price dropped a pip, if the match price didn't drop the bot would change the buy side bid by another 5000 shares and retest the match price. Happened for a few minutes until the bot finally received a 4.7 match price, and then it stopped changing its bid. Unfortunately this happens all the time but it's good to be aware of the broker closing price manipulation for sure.