Larger, more complex transactions dominate 2025 as deal value growth outpaces volume
Global mergers and acquisitions roared back in 2025, but the real story isn’t just the rebound but the scale.
Deal values climbed to nearly US$5 trillion, rising 37% year-on-year and far outpacing the 12% increase in deal count. The imbalance highlights a decisive shift toward larger, more complex transactions reshaping the global M&A landscape, according to a new report from Marsh.
At the top end of the market, mega deals made a strong comeback. Transactions exceeding US$10 billion surged nearly 80% to 70 deals, while deals above US$1 billion rose 28% to 617. The result is a market increasingly defined by fewer, but significantly larger, transactions.
“M&A surged in 2025, with a significant increase in deal value alongside steady growth in the number of transactions completed globally,” said Craig Schioppo, global head of transactional risk at Marsh. “As in prior years, transactional risk insurance remained a vital tool for mitigating risk and enhancing deal certainty for both strategic and financial buyers.”
Capital is concentrating into bigger opportunities, and competition for large-scale assets is intensifying.
The rise in mega deals has been supported by improving market conditions, particularly in the US, alongside stronger investor appetite for scaled transactions. Larger deals are also becoming more complex, often spanning multiple jurisdictions and requiring more sophisticated structuring.
At the same time, deal size growth is not limited to the very top of the market. Average transaction sizes increased across several regions, with North America reaching an average insured deal size of more than US$400 million, while other regions also reported notable gains.
Corporate buyers continue to play a leading role in this environment, outpacing private equity firms globally. Strategic acquirers are increasingly pursuing transformative deals to drive growth, expand capabilities, and secure competitive positioning.
For advisors, this shift toward scale is reshaping both opportunity and risk. Larger deals typically involve longer timelines, more complex negotiations, and heightened execution demands — but they also offer greater potential upside for clients positioned to participate.
The trend also signals a more selective deal environment. While overall activity has increased, the concentration of value in large transactions suggests capital is being deployed more strategically, with investors prioritizing high-quality assets over volume.
Looking ahead, the momentum behind large-scale M&A is expected to continue into 2026, supported by improving financing conditions and significant levels of undeployed capital. However, geopolitical uncertainty could still influence deal timing and execution.
Navigating this environment will require a sharper focus on sourcing, structuring, and competing for increasingly larger and more complex deals.
