US stock futures were flat on Friday as markets approached the end of a holiday-shortened week, just moments before a major technical outage at the Chicago Mercantile Exchange (CME) forced a halt in futures and options trading.

The CME glitch — caused by a cooling failure at the CyrusOne data center — halted live trading across multiple asset classes, including equities, commodities, and US Treasury futures. The freeze disrupted trading in key contracts such as S&P 500 (ES=F), Dow Jones (YM=F), Nasdaq 100 (NQ=F), and crude oil, leaving traders without access to the world’s largest derivatives platform for several hours.

Before the outage, futures were modestly higher. Dow Jones Industrial Average futures were up 0.1%, S&P 500 futures gained 0.1%, and Nasdaq 100 futures added 0.2%, as investors cautiously positioned ahead of the month-end.

The pause comes as Wall Street looks set to close November in the red. A sharp pullback in mega-cap tech stocks has dragged the Nasdaq down 2% so far this month, putting the index on track to end its seven-month winning streak. The S&P 500 and Dow are also slightly negative for November, threatening to break a six-month run of gains.

With trading on CME still halted, investors will be watching closely for updates on when the exchange will resume operations — and how the sudden freeze may impact price discovery heading into the weekend.