This article on overnight futures trading is the opinion of Optimus Futures
What Is an Overnight Position?An overnight position is simply any position held beyond the market close. Later today, for example, the ES will stop trading at 5pm EDT. But “tomorrow’s” trading day begins an hour after close, at 6pm EDT. Confusing? It can be. There is no “overnight” close. The ES trades around the clock from Sunday 6pm to Friday at 5pm with one hour close at the end of each weekday. “Overnight” is a misleading term, simply because most commodities trade around the clock (24-hours) five days a week. Many day traders, particularly new ones, make the mistake of holding positions overnight. Sometimes the mistake is unintentional, and other times it is intentional but poorly thought-out.