GlobalData’s latest league table placed Sullivan & Cromwell first by deal value and Alston & Bird first by deal count among legal advisers on financial services mergers and acquisitions (M&A) in the first half of 2026. 

Using data from its Financial Deals Database, GlobalData reported that Sullivan & Cromwell worked on transactions worth $24.9bn, the highest total by value. Alston & Bird recorded the highest number of mandates, with 23 deals. 

In the value ranking, White & Case was in second place with $18.6bn, followed by Clifford Chance on $18.2bn, Paul, Weiss, Rifkind, Wharton & Garrison on $16.9bn, and Latham & Watkins on $16.7bn. 

In the volume table, Kirkland & Ellis ranked second with 22 deals. Simpson Thacher & Bartlett followed with 21, while Latham & Watkins advised on 20 deals. 

GlobalData lead analyst Aurojyoti Bose commented: “Alston & Bird was the top adviser by volume in H1 2025 and retained its leadership position by this metric in H1 2026, despite a year-on-year decline in the total number of deals advised by it. 

“Similarly, there was a decline in the total value of deals advised by Sullivan & Cromwell in H1 2026 compared to H1 2025. However, it remained well ahead of its peers in terms of value. Sullivan & Cromwell also occupied the fifth position by volume with 16 deals.” 

GlobalData’s league tables are based on the real-time tracking of thousands of company websites, advisory firm websites and other reliable sources available on the secondary domain. A dedicated team of analysts monitors all these sources to gather in-depth details for each deal, including adviser names.   

To ensure further robustness to the data, the company also seeks submissions of deals from leading advisers.