Pre-market orders placed between 9AM and 9:08AM is the quickest way to get in or out of a trade as soon as the market opens.
Many beginners in a hurry to get the big buck would be tempted to use this without analyzing these risks involved:
1) Pre-market orders placed cannot be modified or cancelled between 9:08AM and 9:15AM and once the market opens it would be too late before you can change your mind.
2) Pre-market orders placed based on some overnight news might not give you a clear direction by itself unless you give time for the market to open and determine the direction of price reacting to the news.
3) Pre-market orders placed based on BUY SELL QTY alone during the pre-open session does not determine the direction of price, since most of these orders are proxy orders placed far away from the trading price not intended to be filled but to mislead beginner traders to inflate demand or supply.
4) Opening 15 mins are subject to huge price volatility, and if you are caught up on the wrong side of the trade with a leveraged position, you capital could be wiped off very quickly before you even get sufficient time to save it.