Reuters reported that a Microsoft 365 outage exceeding 12 hours disrupted businesses and government agencies across several countries, as Microsoft shares fell in U.S. premarket trading Nov. 13.
Market reports captured different points in the session. Dow Jones put Microsoft shares at about $509, down 2.7%, at 5:31 a.m. ET. Reuters later reported a 1.7% decline at 7:30 a.m. ET. NDTV Profit's article body gave a price of $518.62, down 0.84%, at 9:17 a.m. ET, while its headline and summary cited a 2.1% decline. NDTV Profit also described Microsoft as the only decliner among the Magnificent Seven. A prior EconoTimes report found that Magnificent Seven stock returns diverged over the year.
Microsoft's service notices listed Exchange Online, Teams, SharePoint Online and Microsoft 365 Copilot among the affected products. The company said some servers became unavailable after failing automated health checks. It also identified an overloaded core process that was reducing capacity.
Microsoft said early results from a patch to an upstream authentication and routing component showed improved server stability on part of its infrastructure. The company was monitoring the change and planned to extend it to servers supporting active regions. After mitigation, Microsoft said it would release a review explaining the outage's cause and the steps taken to address it, but gave no publication time.
Reuters reported disruptions at Euronext, Aviva and Maersk. The news agency also said one Taiwanese financial firm canceled a bond repurchase transaction and another used fax to confirm trades, citing people familiar with the firms' responses. Reuters reported that the expense and complexity of replacing Microsoft’s software can deter customers from switching, and noted the company had faced another Microsoft 365 disruption earlier in 2026 and an Azure outage the month before.
Josh Gilbert, a market analyst at eToro, told Reuters that recurring reliability problems could lead IT departments to reconsider adding more work to a single provider. Microsoft's post-incident review is the next update identified by the company.
