Major Trading Halt Disrupts Global Financial Markets
A significant technical failure at a key data centre brought trading of futures and options on the Chicago Mercantile Exchange (CME) to an abrupt halt on Friday, November 28, 2025. The outage, which lasted for several hours, caused widespread disruption across global equity markets, foreign exchange, bonds, and commodities, leaving traders in the dark during a critical trading session.
Root Cause: Cooling System Failure
The malfunction was traced back to cooling system problems at a CyrusOne-operated data centre in the Chicago area. According to a spokesperson from the facility operator, engineering teams worked to restart several chillers and deployed temporary cooling equipment to address the issue. The company did not provide an immediate timeline for when normal operations would fully resume, leaving market participants uncertain about the duration of the disruption.
This outage has already surpassed the duration of a similar technical failure that occurred in 2019, highlighting the extensive reach and critical importance of CME Group Inc. and its electronic Globex trading platform. The interruption triggered widespread frustration as traders contemplated the possibility of an entire lost trading session.
Widespread Market Impact and Trader Frustration
The trading halt affected millions of contracts that track major indices like the S&P 500, Dow Jones Industrial Average, and Nasdaq 100, which typically trade virtually around the clock on the CME, one of the world's largest derivatives exchanges.
Thomas Helaine, head of equity sales at TP ICAP Europe in Paris, described the situation as "a bit like flying dark." He explained, "When you're trading cash equity like us, U.S. futures give you an indication of where the market is going before the open. I can only imagine how complicated it must be for derivatives desks."
The outage specifically halted trading of U.S. Treasury futures, though European and UK bond markets trading on different exchanges remained unaffected. The EBS platform, used in foreign exchange markets, was also impacted, which hurt price discovery mechanisms.
Gnanasekar Thiagarajan, head of trading and hedging strategies at Kaleesuwari Intercontinental, confirmed the sentiment among traders, stating, "Traders sitting with a position are certainly quite angry."
Commodities and Derivatives Face Additional Complications
The timing of the Friday disruption created particular inconvenience for traders needing to roll positions from one monthly contract to another. In commodities markets, the outage coincided with the expiry day for gasoline and diesel futures that can be settled with physical fuel delivery, adding another layer of complexity.
Gold experienced erratic moves during early London trading, with the gap between bids and offers widening to about twenty times the normal range. U.S. crude oil and palm oil on the Bursa Malaysia exchange were also affected by the technical problems.
The disruption created significant challenges for equity-derivatives desks, particularly with options on the S&P 500 representing roughly $600 billion in notional value set to expire on the same Friday. While these contracts trade on the CBOE market, traders typically use CME-listed futures for delta-hedging their positions.
Oliver Deutschmann, head of equity derivatives EMEA at Liquidnet, noted that some traders might attempt to use ETFs and Euro Stoxx futures as alternatives for delta-hedging SPX option positions, though he emphasized that neither provides a perfectly clean hedge.
