Quote from Eliot Hosewater:
Two questions:
1. Don't you always buy at the ask and sell at the bid? If you put in a limit order and it gets filled doesn't that just mean that the market has moved enough to meet your price? If so, then it really means that the market has moved against you? Let's say you want to buy at 1.70 but the current price is 1.90. The market would have to move down to meet your price, but in the long run you want it to be going higher.
2. Last Friday (Oct expiration) I put in a limit order to BTC an IC on GOOG about three minutes before closing. I put the order in at $5 which was the natural at the time. I waited about a minute before getting filled, but the TOS screen showed the natural price going down as far as 4.50. Does that just mean there was probably a backlog due to high volume, or did my 5.00 order get executed when it could have been done for 4.50? Isn't a limit order for your price or better?
1. That's correct, however this is not considered slippage since you got the price you wanted.
2. A limit order is at your price or better. However, an iron condor has 4 legs, which are generally filled on a single exchange (you can get it filled on different, but I'd say it's unlikely at the close of expiration friday) while the composite bid-ask quote is coming from all exchanges.