The market makers use all the information that they can, but they do it on an aggregate level. It's the same as any other big tech giant harvesting their user data. Unless your order is huge enough to move the market you don't have to worry
they dont do it in personal level because they dont have that info or because they dont care? if you dont know please dont answer
I guess the only folks on the forum who would truly know the answer are market makers. Do we have any market makers on the forum, the entities you are so concerned about? Let's wait and see if any chime up.
Your order size is too small for them to spend the effort to write a specific algo to exploit it. Unless you are a huge fund doing size.
I remember @cruisecontrol mentioning that some brokers do provide account level info, which he confirmed with them. I would not be surprised if that happens since whoever is buying the orders don’t want any toxic flow.
This is a good question....and one may be worried if trading illiquid instruments or trading that time of day when volume is a trickle.. You will know when is the time to trade an instrument so that you are not the one caught on wrong side of things..