CHICAGO — A CME outage halted most electronic futures and options trading across its Globex platform at the world’s largest derivatives marketplace, CME Group, early Friday, freezing benchmark contracts for U.S. stock indexes, crude oil , and Treasuries. The suspension came after a cooling-system failure at the CyrusOne data center in Aurora, Illinois, causing some servers to overheat and forcing CME to close markets around the world until engineers brought temperatures down and verified that systems were safe, Nov. 28, 2025.
How the CME outage unfolded
The CME outage, which kicked off late Thursday night after CME’s global command center cited technical problems and, later, a cooling issue at its Chicago-area CyrusOne facility, transported trillions of dollars in assets to its network of out-of-state backup data centers. Messages on the exchange’s global command center system’s alerts page indicated that Bursa Malaysia Derivatives, the EBS currency platform, and, eventually, all Globex futures and options markets were halted as trading kicked off in Asia.
Shortly before dawn in Chicago, CME informed clients that Globex futures and options would pre-open at 7 a.m. Central time and resume trading at 7:30 a.m., canceling day orders but leaving good-’til-canceled orders intact. Reuters, in a short update dispatched and posted online, confirmed the timing described by Driscoll and said CME had published on its website several hours beforehand that it was experiencing an outage, suggesting the CME failed to trade for about 10 hours.
Worldwide effects and low holiday volumes
The CME outage halted trading across a range of contracts used to hedge or make speculative bets on movements in equity indexes, U.S. Treasuries, energy products, metals, and foreign exchange markets, as well as key equity, energy, and currency benchmarks. CME’s operator, CyrusOne, blamed the failure on cooling issues at its Aurora-area data center, which led to a spike in temperatures and service disruptions for clients such as CME, according to a Yahoo Finance report. Desks that use CME prices to hedge risk in cash markets and over-the-counter derivatives markets had been effectively flying blind for much of the night.
Although the incident sent traders reeling, its timing likely mitigated more widespread damage. The stop came on a truncated post-Thanksgiving Black Friday session that often sees light volume, and equity futures were modestly positive as they reopened, MarketWatch reported. Business Insider said CME’s follow-up posts on X emphasized that markets were “open and trading” once the technical issue was resolved, even as desks braced for choppy moves in a low-liquidity session.
A familiar hint for a marketplace infrastructure
The CME outage on Friday will be reviewed as one of the longest trading interruptions in years at a core piece of global financial plumbing. MarketWatch documented this technical error in 2019 that led CME to shut down electronic trading across all Globex futures markets for hours before returning to normal trading, a reminder of how much of the world’s hedging and price discovery runs through one platform. A Brookings analysis of the New York Stock Exchange’s 2015 meltdown also urged that ageing cyberinfrastructure and single points of failure can turn a routine glitch into a systemic scare.
In the coming days, CME, CyrusOne, and regulators are likely to investigate why backup systems and other data centers were unable to withstand such a lengthy shutdown — and whether even greater redundancy or failover testing is necessary. For traders, the CME disruption is a fresh reminder that, in an age of algorithmic execution and 24-hour electronic markets, a routine breakdown like a failed chiller can render the world’s largest derivatives exchange powerless.
