I don't have much experience with this but I'm curious. How likely is it that there are hidden orders inside the spread and why would anyone be placing such orders? What is the point if the internalizing brokers are allowed to steal all your fills?
Seems to me like market orders don't make much sense for large spread stocks unless you need to get in or out super urgently. What about putting in a limit order at the midpoint or at 3/4 of the spread depending on how aggressive you are.
I was replying to the OP actually, sorry if that was unclear.
by margin rates I meant the interest rate, not margin requirement.
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1.those "hidden orders" exist because of those bastards hft. if you show your orders inside the spread, they will front run your order by penny jump, bringing your stock price to the heaven or to the hell, before they cancel their orders and put a new order in the opposite side!
2. i am not sure 100%, nobody can say whats really happen. i am pretty convinced that a BIG prop hft firms like "Timber hill" or someone else is pluged into IB orders servers with their non official acknoweldgment. and they adverse select you and me....they eat billions on our heads.
ask a question: why ib take us insane fees if we wish to direct route? in fact why do they force us to use their so smart "SMART" router?
why they dont supply post-only or alo orders, if they are only a broker?
3. the first thing you need to look at to reduce that problem is first:
effective spread vs displayed spread, in real time it give you an idea of the 3/4 you were talking about.
seconds, you need to feed your algo with the orderflow (orderflow can be calculated different ways, took me severals years to have a robust order flow calculation)
at the end, make your SOR....
all what i told here is sensitive if you do algo trading, otherwise forget it...
rgds,