Let’s say you want to buy 1000 shares of an illiquid stock. Rather than waiting for someone else looking to sell exactly 1000 shares, you could be matched with person A selling 600 shares, and person B selling 400 shares. Similarly you could be matched with person C selling 20,000 shares.
There is no price discrepancy, your order was simply filled in more than one step during which the market has moved.
I’m not 100% on the fractional part - I assume if 212 have someone looking to sell a fraction of a share that hasn’t executed through IB, then they will match with someone looking to buy first and then leave the remainder open.
To understand if you got a fair market price (and you should have), you will need to check the exchange on book prices.
There may be, depending of the price person A and B are willing to sell at.
Also in the case of T212, this is often due to part of your order being match on their own extra allocation on their books (the order venue will be OTC) and the rest of the market (i think it shows “trading venue” or “market”?).
With only one split, the price should be about the same, and both should be executed at market price.
With multiple splits (one OTC, many actual venues), each of the actual venue trades may have a different price, and in my experience T212’s price will be in that range, sometimes the best price, sometimes not.
I thought that since the price was different between the “two” orders, the price would have been better if there was only one order, but I understand now that no and if it would have been one single order then it would have been at the highest price? is it correct ? so somehow I’m “winning”?