When buying authority certificate recently, clinch a deal finally the price that valence inputs than me unexpectedly nearly 5 minutes taller money, have other measure excuse me of the oldest rate reduce the price difference when clinching a deal?

• 最近一次买权证时，最终的成交价比我输入的价竟高了近5分钱，请问有没有别的办法最大程度的降低成交时的价差?