Cooling failures at CME’s primary data center began 12 hours before global trading halted, with procedural errors and shifting severity assessments delaying response. The exchange declined to activate its disaster backup site, resulting in widespread disruption across metals, energy, rates, and FX markets, highlighting concentrated dependence on a single external infrastructure provider. I. Incident Overview In late November 2025, CME Group suffered a technology failure at its primary data center in suburban Chicago, interrupting global derivatives trading across asset classes. The outage originated at CyrusOne, the ... (full story)