
(Update) November 28, 2025, 11:00 AM GMT: Article updated.
Trading of futures and options on the Chicago Mercantile Exchange was halted by a data-center fault, causing hours of disruption to markets across equities, foreign exchange, bonds and commodities.
The malfunction was caused by cooling system problems at a data center in the Chicago area, according to facility operator CyrusOne. Engineering teams have restarted several chillers and deployed temporary cooling equipment, a spokesperson said, without giving a time for the resumption of normal operations.
The halt is already longer than a similar, hours-long outage due to a technical error back in 2019 and underscores the reach of CME Group Inc. and its Globex electronic trading platform. It triggered widespread frustration as market participants contemplated the prospect of a lost trading session. Millions of contracts tracking the S&P 500, Dow Jones Industrial Average and Nasdaq 100 trade every weekday virtually around the clock on the CME, one of the world’s largest derivatives exchanges.
“It’s a bit like flying dark,” said Thomas Helaine, head of equity sales at TP ICAP Europe in Paris. “When you’re trading cash equity like us, US 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 halted trading of US Treasury futures, while European and UK bond markets that trade on a different exchange were unaffected. EBS, a platform used in foreign exchange, was impacted, hurting price discovery in the market.
For some traders, the timing of the disruption on Friday could cause particular inconvenience if it lasts, due to the need to roll positions from one monthly contract to another.
“Traders sitting with a position are certainly quite angry,” said Gnanasekar Thiagarajan, head of trading and hedging strategies at Kaleesuwari Intercontinental.
Gold saw erratic moves in early London trading, with the gap between bids and offers about 20 times wider than normal. US crude oil and palm oil on the Bursa Malaysia exchange were also affected. In commodities markets, Friday is the expiry day for gasoline and diesel futures that can be settled with delivery of the actual physical fuel, adding a further potential complication.
The disruption created challenges for equity-derivatives desks. Options on the S&P 500 representing roughly $600 billion in notional value were set to expire on Friday, according to data compiled by Bloomberg. While those contracts trade on the CBOE market, traders use CME-listed futures to delta-hedge their positions.
Some traders may attempt to use ETFs and Euro Stoxx futures delta-hedge SPX option positions, said Oliver Deutschmann, head of equity derivatives EMEA at Liquidnet, but neither provides a clean hedge.
“Market-makers may pull screen quotes and clients might struggle to get meaningful size done until futures resume trading,” Deutschmann said.
Lost Liquidity
Others reported that volumes had shifted onto alternative, operational platforms as liquidity and price transparency evaporated.
“Traders will be switching to alternative liquidity tools where they can,” said Nick Twidale, chief analyst at AT Global Markets in Sydney. “We’ve lost one of the market’s major liquidity sources. This heightens the risk of exacerbated moves if a big event occurs.”
Most US markets were closed on Thursday for the Thanksgiving holiday, and are due to reopen later for a shortened trading day. Thankfully for traders, there is limited news expected on Friday with no economic data scheduled for release in the US, and there are no expected Federal Reserve speakers ahead of a blackout period leading up to their anticipated December decision.
November has been a volatile month for equities, with the S&P 500 slumping as much as 4.7% amid concerns about the path of Fed rate cuts and valuations about artificial intelligence-linked stocks. The index has clawed back those losses and volatility has been falling all week, back near October lows. The US stock benchmark is close to erasing its monthly drop with one more session left before the final month of the year.
Bourses operated by CME include the Chicago Board of Trade, the New York Mercantile Exchange and the Commodity Exchange. CME also has a stake in other exchanges, including the Gulf Mercantile Exchange, which said in a notice to the market that it had also seen trade halted due to the cooling issue.
CyrusOne did not immediately respond to Bloomberg queries.
WHAT DO YOU THINK?
Generated by readers, the comments included herein do not reflect the views and opinions of Rigzone. All comments are subject to editorial review. Off-topic, inappropriate or insulting comments will be removed.





















