CME products stop for roughly an hour each weekday afternoon, typically 5:00-6:00pm Eastern. It is not a trading-halt: it is scheduled, and it separates one trade date from the next.
Positions carry through, but resting orders behave differently depending on their duration: a day order dies at the break while a good-till-cancelled order survives. Misunderstanding this leaves traders unprotected overnight.
Example: a stop placed as a day order on Tuesday afternoon is cancelled at 5:00pm. If the trader assumed it was still working, the overnight position has no stop at all.
Related: globex, good-till-cancelled, day-order, daily-settlement, overnight-session