Chicago, United States - December 1, 2025 - CyrusOne has installed additional backup cooling capacity at its Aurora, Illinois, data center complex after a chilling-system failure at the site triggered a multi-hour outage that halted trading on CME Group’s futures and options platforms. The added equipment, described in company and market updates as temporary and supplemental chillers and pipework to bolster resilience, was mobilized while engineers worked to stabilize the primary chilled-water system.
The outage, which began late on Thursday and extended into Friday’s thin, post-holiday trading session, disrupted CME’s Globex electronic matching engine and the EBS FX platform, leaving benchmark prices for S&P 500 and Nasdaq futures, US Treasuries, oil and gold effectively frozen during the stoppage. CME’s Global Command Center posted repeated alerts attributing the interruption to the CyrusOne cooling incident and notifying clients that support teams were working to restore services and publish pre-open timings.
Brokers and trading desks reported suspensions of automated strategies and reliance on internal pricing models while the exchange was offline, with downstream exchanges and venues that ingest CME feeds also affected or pausing activity.
Traders told reporters the timing, at month-end and amid holiday-thin liquidity, amplified the operational risk and complexity of re-establishing orderly price discovery once systems came back online.
CyrusOne and CME said their immediate focus was remediation rather than technical attribution; public statements and wire coverage describe a sequence of contractor callouts, chiller restarts, and temporary cooling deployments to reconstitute chilled-water circulation.
CyrusOne’s swift action to add standby cooling capacity, and said exchange teams coordinated closely with site engineers to prioritize market restoration.
The incident has prompted fresh scrutiny of concentration risk across financial-market infrastructure, where a small set of collocated data centers and service providers underpin global price formation. Market participants and resilience specialists say the episode underlines the need for redundant, geographically diverse cooling and power architectures and for clearer contingency routings for critical market feeds, even as operators weigh the cost and complexity of N+1/N+2 mechanical designs and rapid-response mobile cooling options. Regulators and exchanges typically follow such outages with structured after-action reviews; participants said they expect formal reports once systems are fully recovered.
