Global mergers and acquisitions activity rose for the second consecutive year in 2025, with 726 deals valued over $100 million completed during the 12-month period.
The figures, released by WTW in its Quarterly Deal Performance Monitor, represent a 2% increase from the 710 transactions recorded in 2024.
The report, produced in partnership with the M&A Research Centre at Bayes Business School, found that acquirers nearly matched the performance of companies pursuing organic growth.
The performance gap narrowed to -0.5 percentage points in 2025, compared to -10.9 percentage points in the prior year. Despite stock markets reaching record highs, 32% of companies that completed deals outperformed the broader market.
The total value of completed transactions reached $933 billion, an 11% increase from 2024. Large deals valued over $1 billion drove much of the activity, with 201 such transactions completed compared to 177 the previous year – a 14% rise. The average size of large M&A deals also reached a record $2.9 billion in the second half of 2025, a 23% year-on-year increase.
The appetite for large transactions was particularly evident in Q3 2025, when eight megadeals valued over $10 billion closed globally. This marked the highest quarterly volume of megadeals since Q4 2018, according to previous WTW data.
Jana Mercereau (pictured above), head of Europe M&A consulting at WTW, noted that while large transactions are shaping the market, they carry elevated risk.
"Major investments grounded in sound strategy have the potential to reshape a business and establish a path for sustained growth," Mercereau said. "On the other hand, deals that lack a well-defined, strategic objective can become a recipe for value destruction."
Mercereau said deal activity improved throughout the year, supported by equity market performance, interest rate reductions, and AI adoption.
She added that "targeted scale will remain key as the market continues to reward larger companies with the capacity to weather sharp and unpredictable swings in M&A activity that have become the 'new normal' for dealmakers, buffeted by persistent geopolitical turbulence."
