Global M&A Deal Value Rises 23.9 Percent as Mega Deals Surge

Global mergers and acquisitions (M&A) deal value increased 23.9 percent during the first 9 months of 2026, driven by a record number of mega deals, according to WTW's Quarterly Deal Performance Monitor (QDPM).

The value of completed transactions rose to $1.65 billion from $1.33 billion during the same period in 2025. The report, produced in partnership with the M&A Research Centre at Bayes Business School, found that 24 mega deals valued above $10 billion were completed during the 9-month period, the highest total on record.

Mega deal activity accelerated in the third quarter, with nine transactions completed, compared with three in the previous quarter.

Overall deal volume increased 16.1 percent year over year, reaching 614 transactions compared with 529 in the first 9 months of 2025. However, quarterly activity declined slightly to 200 completed deals from 202 in the second quarter. Large transactions valued between $1 billion and $10 billion decreased to 45 from 48.

Deal execution also accelerated. Transactions completed within 70 days of announcement accounted for 43 percent of third-quarter activity, up from 35 percent in the previous quarter. Cross-sector transactions increased to 35 percent of deals from 25 percent.

"Mega deals continue to reshape the global M&A landscape, as companies move decisively to build scale, close capability gaps, and secure critical technologies in an increasingly competitive market," said Jana Mercereau, head of Europe M&A consulting at WTW.

"While faster deal execution reflects the increasingly dynamic nature of today's M&A environment, shaped by [artificial intelligence]-driven transformation, geopolitical tensions and macroeconomic uncertainty, speed must not come at the expense of rigorous due diligence. Companies that prioritize pace over discipline risk undermining long-term value creation and increasing the likelihood of post-closing challenges."

Despite increased activity, acquisition performance remained weak. Global dealmakers underperformed companies not engaged in M&A for the second consecutive quarter, trailing the benchmark index by 10.3 percentage points.

Of the 200 completed transactions in the third quarter, 121, or 60.5 percent, underperformed their respective indexes, while 79, or 39.5 percent, outperformed.

North American acquirers underperformed their regional index by 13.8 percentage points, completing 109 transactions compared with 103 in the previous quarter.

European acquirers trailed their benchmark by 5 percentage points, completing 37 deals. European transaction volume declined for the fourth consecutive quarter, down from 47 deals in the third quarter of 2025. UK buyers, however, outperformed their regional benchmark.

Asia-Pacific acquirers recorded the weakest regional performance, underperforming by 18.7 percentage points. Deal volume fell to 43 transactions from 51 in the second quarter. Chinese buyers increased their activity to 21 completed deals from 7.

"Corporate buyers continue to show remarkable resilience despite persistent market headwinds," Ms. Mercereau said. "Even amid rising interest rates, surging energy costs and November's US midterm elections, dealmakers are expected to press ahead with strategic transactions, particularly at the upper end of the market."

The WTW study examines completed acquisitions valued at $100 million or more, using transaction data from LSEG. Acquirer share-price performance is measured from 6 months before the deal announcement through the end of the quarter and compared with relevant market indexes.