Hi I bought 100 stocks of AAPL using a MKT order before the trading opened[which was marked to not be filled outside of trading hours] but I see I got filled at 117.34 while the official open price was 117.50. is it because I'm using the paper account? what is the best way to "capture" the day open price? Thanks in advance (I see I got filled by ARCA if that matters)