If you truly believe that a stock will go up (say on excellent news release)you need to buy it on the ask otherwise it will not execute. Or, you can wait for the first run to be over, put in your buy order lower in advance and hope when it takes its' first dip it fills.
Learn to place limit orders and put them in before the bell. I find I can modify an order as fast or faster than I can originate one from scratch. They are subject to the broker approval but I have never had a problem with that.
My opinion would be depending how high of a percentage the stock opens up just buy if u feel it will continue going up have seen it dozens of time more then triples after the open....