I placed an OPG buy order submitted at 7:30 AM with the broker Optionshouse for a stock that trades on the NYSE, and instead of being placed at the listed open of $7.80 (opening price according to yahoo) it was placed at $8.00. Why would this occur? Would optionshouse compensate me for this mistake? And are there any other brokers that place reliable OPG orders because optionshouse isn't doing a good job on this? This stock trades on the NYSE so my understanding is that it would have to be placed at $7.80. Is this correct?
You have to ask Optionhouse where their OPG orders go and why they are different. I also can't tell you that Yahoo is the best source to see what the opening was on the primary. I don't know if they list the first trade or the primary as the opening.
Each company is listed on an exchange. That is the primary. Eg GE and IBM are listed on the NYSE. AAPL and CSCO are listed on the Nasdaq, that is their primary exchange.
I think I misunderstood. When you said "I don't know if they list the first trade or the primary as the opening." I took this as meaning there was two different opening prices. I was under the impression there was only supposed to be one and that places like google and yahoo finance listed them.
THis is what I expect is true. The opening sale on trading platforms is typically the 1st sale, not necessary the primary. It is possible for an ECN to open a fraction of a second earlier than the primary. They don't have to wait. I can only tell you that the opening quote on the primary is where the volume and auction process will be held, and that is where I want my order sent. You want your order there for a fair open/close. It is possible that an online broker like Optionhouse sends their orders to an equity MM that handles it on a best efforts basis, but you have no price protection at 9:30am ET.
Since you didn't mention what you were trading and I'm too lazy to figure it out, it's hard to say exactly but most probably you're talking about the consolidated open while your OPG was directed to the NYSE open, just as Robert says.
Look up open and closing auctions do NYSE and Nasdaq. The exchanges open price can be different then the official opening price as the official open( that pretty much everyone shows as open ie:Yahoo,Google), is the first transaction after 9:30 opening. That order could be from any exchange, not part of the primary exchanges auction process. When you send a market on open order, it should be directed to that stocks primary exchange for their open auction. Nasdaq and NYSE have a bit of a different process so could read up on both.