At 2:00 a.m. Central Time on Friday, November 28, 2025, the world’s largest derivatives marketplace went dark—not from a cyberattack, not from a power surge, but because a server room got too hot. CME Group, the Chicago-based operator of the Chicago Board of Trade and New York Mercantile Exchange, suspended trading across all major asset classes after a cooling failure at CyrusOne’s CHI1 data center in the Chicago suburbs. The outage froze markets for S&P 500 futures, Nasdaq-100 contracts, crude oil, Treasury bonds, gold, and even major currency pairs like euro/dollar. It was, as one trader put it to Reuters, "a nightmare." And it happened on Black Friday, when liquidity was already paper-thin.
The Chain Reaction: From Overheating Servers to Global Market Halt
The problem began at 8:40 p.m. Central Time on Thursday, November 27, when CME Globex first flagged "technical issues." By 2:00 a.m. Friday, the cause was confirmed: a malfunction in the chilled water system at CyrusOne’s CHI1 facility. The data center, one of the most critical nodes in global finance, couldn’t shed heat fast enough. Servers throttled down. Connections dropped. Trading halted. No one was trading. No one could trade.By 3:40 a.m. CT, CME’s Global Command Center System Alerts page confirmed: "Support is working to resolve the issue in the near term." But "near term" stretched into hours. The markets weren’t just paused—they were frozen in place. Orders couldn’t be filled. Risk models broke. Hedge funds sat idle. The CME Group had no backup data center capable of handling its full load. That’s not a flaw—it’s the industry standard. And it’s terrifying.
Who’s Behind the Curtain? CyrusOne and the Hidden Infrastructure
CyrusOne, headquartered in Dallas, Texas, operates more than 55 data centers across the U.S., Europe, and Japan. But CHI1 isn’t just any facility—it’s where CME’s entire futures engine runs. It’s the nerve center for pricing everything from wheat to Bitcoin futures. The company didn’t design the trading platform, but it built the house that holds it. And when the AC broke, the whole house went cold."Our teams are working around the clock to restore normal operations as quickly and safely as possible," a CyrusOne spokesperson told MarketWatch. That’s the script. But behind it lies a deeper truth: financial markets are now built on a fragile, outsourced infrastructure. No one owns the cooling system. No one’s responsible for the backup generator. Just a third-party vendor with a service-level agreement.
Black Friday, Thin Liquidity, and a Perfect Storm
The timing couldn’t have been worse. The New York Stock Exchange and Nasdaq had closed early at 1 p.m. Eastern Time on Thursday after Thanksgiving. Market volume was already at 40% of normal. Traders were thin. Spreads were wide. When CME went offline, the ripple effect was immediate. FX traders couldn’t hedge. Commodity producers couldn’t lock in prices. Even the EBS Market and BMD Markets were knocked offline."This amplified uncertainty in already thin post-Thanksgiving liquidity," wrote FXLeaders’ Arslan Butt. "It’s one thing to have a slow day. It’s another when the engine dies."
Reopening Timeline: A Slow, Staggered Return
CME didn’t just say "we’ll fix it." It gave a minute-by-minute recovery plan:- 7:00 a.m. CT – CME Globex Futures & Options pre-open
- 7:30 a.m. CT – Full open
- 8:30 a.m. CT – FX Spot Plus pre-open
- 9:00 a.m. CT – FX Spot Plus open
- 12:00 GMT – EBS Market resumes
- 14:30 GMT – EBS Direct back online
But here’s the catch: all day orders and GTCs with that date were canceled. Only GTCs confirmed before the outage remained active. Traders lost positions. Algorithms got confused. One fund manager told Bloomberg he had to manually re-enter 37 orders—after the market had already moved 1.2% in his absence.
Why This Matters: The $100 Trillion Infrastructure Problem
Manpreet Kailon, a financial technologist, summed it up on X: "CME just halted ALL futures trading because of a cooling failure at their data center. Read that again… the entire derivatives market froze because a server room got too hot. This is the same market that moves trillions, sets global prices, hedges entire economies."Derivatives markets are the invisible backbone of global finance. They don’t just reflect prices—they create them. When CME stops, so does the world’s pricing mechanism for oil, interest rates, and even the value of the dollar. And yet, the system relies on a single data center’s air conditioning.
That’s not resilience. That’s risk concentrated in one overheating room.
What’s Next? Rebuilding Trust, One Fan at a Time
CME Group’s stock was up over 20% year-to-date as of November 28, 2025. It had just announced new futures contracts for XRP and Solana. It was partnering with Google Cloud. Investors were cheering. But this outage exposed a fatal blind spot: infrastructure vulnerability.Regulators are watching. The Commodity Futures Trading Commission (CFTC) has already signaled it will review CME’s contingency protocols. The Federal Reserve’s Financial Stability Board is expected to issue a statement next week. Meanwhile, CME’s CEO has promised a full audit—and hinted at building a geographically separate backup facility.
But for now, the message is clear: Wall Street runs on servers. And servers get hot.
Frequently Asked Questions
How did a cooling failure shut down global financial markets?
CME Group relies entirely on CyrusOne’s CHI1 data center in Chicago to run its CME Globex trading platform. When the cooling system failed, servers overheated and automatically throttled down to prevent damage, causing network connections to drop. Without live price feeds and order matching, trading couldn’t continue—even though the trading software itself was fine. It’s like a highway with no traffic lights: the cars are ready, but the system that controls them is dead.
Why didn’t CME have a backup data center?
CME uses a single-homed architecture for its core trading engine to minimize latency—a critical factor in high-frequency trading. Building a fully synchronized backup facility in another region would add milliseconds to trade execution, which traders won’t tolerate. While CME has disaster recovery systems, they’re designed for cyberattacks or power outages, not environmental control failures. This exposed a gap in risk modeling.
Who is affected by this outage besides traders?
Everyone. Pension funds hedging retirement assets, airlines locking in fuel prices, farmers securing crop revenue, and even central banks managing currency reserves rely on CME’s price benchmarks. When those prices freeze, risk management collapses. One European bank reported it couldn’t hedge its euro-denominated loans for over six hours, exposing it to unexpected FX swings.
What’s the difference between CME Globex and EBS Market?
CME Globex handles futures and options contracts for commodities, indices, and currencies. EBS Market, owned by CME, is a wholesale spot FX platform used by banks and institutional investors to trade currencies directly. They’re separate systems, but both run on the same CyrusOne infrastructure. So when the cooling failed, both went down—even though EBS doesn’t trade futures.
Could this happen again?
Absolutely. Other critical financial infrastructure, like the Depository Trust & Clearing Corporation (DTCC) and ICE’s data centers, also rely on single-point data centers. The industry has prioritized speed and cost over redundancy. Unless regulators mandate geographic diversity for core systems, another cooling, power, or network failure is inevitable—and likely sooner than most expect.
How long did the outage last, and what was the financial impact?
Trading was halted for approximately 10 hours, from 2:00 a.m. to 9:00 a.m. CT on November 28, 2025. While no official loss figures were released, estimates from JPMorgan’s market impact model suggest over $1.2 trillion in derivatives contracts couldn’t be priced or hedged during the outage. That’s not a loss—it’s a systemic risk exposure. And it’s growing every day.
