CME Group Trading Outage Analysis Report (Nov 27-28, 2025)

On November 27-28, 2025, CME Group— the world’s largest exchange operator by market value— experienced a widespread trading outage affecting multiple asset classes. The outage halted trading on its EBS foreign exchange platform (average $60B daily volume in October) and futures contracts spanning FX, commodities (WTI crude, gold, palm oil), U.S. Treasuries (10-year), and stock indices (S&P500, Nasdaq100, Nikkei) [0].

The root cause was a cooling issue at CyrusOne data centers, per CME’s official statement [0]. The outage began around 0240 GMT on November 28, with no immediate timeline for resolution provided. Brokers like CMC Markets and IG reported operational challenges, including pulling affected contracts or relying on internal data to price for clients amid the disruption [0].

Traders faced significant uncertainty, with some describing the outage as a “nightmare” and expecting volatility when markets reopen [0]. CMC Markets noted unnecessary risk-taking to continue pricing for clients, while IG highlighted challenges in a post-Thanksgiving low-volume environment [0].

The outage underscores the vulnerability of global financial markets to critical infrastructure failures. Historical precedents (e.g., 2024 outages at LSEG and Swiss exchanges) suggest potential short-term volatility once trading resumes, particularly for affected futures contracts [0].

Non-U.S. sector performance on November27 (U.S. markets closed for Thanksgiving) showed Energy leading (+1.76%) and Healthcare lagging (-0.12%) [3]. Direct U.S. sector impact remains unobserved as markets were closed during the initial outage period.

CME’s stock closed at $280.87 on November26 (pre-outage), up 1.03% that day. Over Nov20-26, the stock had a positive trend with total volume exceeding 10.8M shares [4]. No price data is available for November27 (holiday) or November28 (outage day) yet.

Major U.S. indices closed higher on November26:

• Russell2000 (+0.82%)
• Dow Jones Industrial (+0.49%)
• S&P500 (+0.28%)
• Nasdaq Composite (+0.22%) [2]

These figures reflect market sentiment before the outage and are not directly related to the disruption.

1. Exact timeline for trading resumption and full service restoration
2. Financial impact on CME (e.g., lost transaction fees, customer compensation)
3. Regulatory response or investigation into infrastructure resilience
4. Detailed root cause analysis (specific CyrusOne data center affected, duration of cooling failure)

• Brokers and traders should review contingency plans for exchange outages, including alternative pricing sources.
• Investors in CME Group should monitor for updates on financial losses and regulatory implications.

• Infrastructure Reliability
  : The outage raises concerns about the resilience of critical financial infrastructure. Users should be aware that such disruptions can lead to market volatility and operational risks [0].
• Operational Risk
  : Brokers relying on CME data face increased exposure to pricing errors or customer dissatisfaction during extended outages [0].

1. CME’s official statements on resumption and preventive measures
2. Market reaction (volatility) in affected futures once trading resumes
3. CyrusOne’s response to the cooling issue
4. Regulatory comments on exchange infrastructure standards

Disclaimer: This analysis is for informational purposes only and does not constitute investment advice. All data is based on available sources as of November28,2025.
Users should conduct independent research before making any decisions.
© 2025 Financial Market Analyst Report