The Chicago Mercantile Exchange (CME) Group experienced a major trading outage lasting over ten hours on November 28, 2025, traced to a human error at a CyrusOne data center in Aurora, Illinois. The incident halted trading on CME's Globex and EBS FX platforms, disrupting critical futures and options markets.
The outage originated when a technician failed to follow standard procedures for draining cooling towers at the CyrusOne facility as outside temperatures dropped. This caused the cooling system to fail, leading to overheating in server rooms hosting CME's Globex platform. Robotic safety systems then automatically shut down the equipment to prevent damage, taking core servers offline.
The disruption had immediate global consequences. Trading in S&P 500 and Nasdaq futures, U.S. Treasuries, gold, crude oil, and currency markets abruptly ceased. Liquidity vanished in key markets like gold and Treasury futures, leaving traders in Asia, Europe, and the United States unable to access live prices or manage positions. CME Chairman & CEO Terry Duffy confirmed the "trading interruption was attributed to a cooling incident at CyrusOne’s Aurora data center."
Notably, the outage revealed strategic vulnerabilities. CME sold the Aurora data center in 2016 and has since relied on CyrusOne to manage the infrastructure. Emergency plans included relocating operations to a backup facility, but CME declined to activate it based on early indications the outage would be short-lived. The cooling loss proved more severe, extending the disruption.
While the event highlighted critical dependencies in global financial infrastructure, available data indicates no direct financial impact on specific cryptocurrency projects. The incident primarily affected traditional financial derivatives rather than crypto markets.
In response, CyrusOne has implemented more stringent cold-weather procedures, increased staffing during extreme weather, and enhanced cooling infrastructure redundancy. The episode has reignited debate about CME's control over essential systems and serves as a wake-up call regarding the physical hardware dependencies of modern electronic markets.
