Fill Quantity


I don't know if it's just me but it seems that a lot of my orders are broken up into smaller orders recently
So if I have a seven lot spread I get filled on 2 than another 2 than another 2 and than another one and they all get filled at the same price so it's not like the price has moved and it needs to be filled at a different price
It seems that it started with the free commissions but I am not sure if that is the side effect or just a coincidence
Did anyone else have these kinds of fills recently ?
Is there any reason for splitting the fills if they have the same price ?


New member
I've always had fills like that. Back when RUT options traded on a few exchanges I would see an order filled at two or three different exchanges, in different amounts and different option prices that came out to the same fill price. Now I suspect the matching software is using different opposite orders to complete yours and that accounts for the breakup into multiple fills.


Just to be clear I am talking about SPX
I never saw this kind of fills before they eliminated the commissions Occasionally I get a separate fill but only because it was filled at a different price Why all of a sudden now they are using software to match different orders ?
Is this have to do anything with order flow ?
Just today I got 12 email alerts for a 7 lot spread from Schwab with the exact same fill on all of them when I normally get just 2 alerts one for the buy and one for the sell
I guess I have to ask them why are they doing this ?


So I emailed Schwab but I did not get much information but I also contacted Tastyworks and they said that it was filled within 1 second but not all at the same time meaning that other people were selling 1 or 2 lots

So it looks like it's a volume issue which is surprising since this is the SPX supposedly one of the the most liquid underlying
I also looked at the volume the same day and indeed it was quite low For the 2925 strike the volume was only 18 on 11/12
Today it picked up some volume at 3251 for the same strike
I guess not many traders expecting a drop which may not be a good thing in case of a sell off