I watch T&S, Level II, and Open Book to check on the bid vs ask ratio,
I sometimes notice that when I buy into an Offer(ask) that is reflecting a certain number it often ends up being filled with no change in the offer? Also it tends to be filled with fractional numbers that I am unable to use.
What is that? Are these MM games where they hide their orders? Or do institutions have some slick way of accumulation\shorting stocks that retailers don't?
I'm not fully aware of the market mechanics. There are a lot of ECN's, each with its own rules, then there are dark pools and who knows what's going on between the prime brokers and DTCC.
As far as I can see in through the usual level 2 services, market makers (and maybe hedge funds / quant funds / HFT guys) seem to have the ability to intercept orders at prices that contain cent fractions. I can never see standing orders at cent fractions in "market depth" views though.