Global M&A Megadeal Value Rises 23.9% Despite 10.3-Point Acquirer Underperformance

Global mergers and acquisitions activity reached a record nine-month high for completed megadeals in 2026, with 24 transactions exceeding $10 billion and total deal value rising 23.9% year over year.

The expansion comes with a significant warning for corporate acquirers and private equity investors: buyers completing transactions in the third quarter underperformed their relevant equity benchmarks by an average of 10.3 percentage points, suggesting that stronger dealmaking activity has not consistently translated into superior shareholder returns.

According to research published by WTW and Bayes Business School, quarterly deal performance monitor recorded 614 qualifying completed transactions during the first nine months of 2026, compared with 529 in the corresponding period of 2025, an increase of 16.1%.

The research covers completed acquisitions valued at $100 million or more that satisfy its methodology. It therefore provides a different view of the market from databases measuring all announced transactions, including those that have not closed.

Megadeals drive global M&A expansion

WTW recorded 24 completed megadeals worth more than $10 billion during the first nine months of 2026, the highest total for that period in the study’s history.

Nine of those transactions closed in the third quarter, compared with three during the preceding quarter.

The figures point to sustained demand for transformational acquisitions even as borrowing costs, geopolitical uncertainty and elevated energy prices complicate corporate investment decisions.

The research also reported a 23.9% year-over-year increase in the value of qualifying completed deals, highlighting the comparison as $1.65 billion against $1.33 billion, although those amounts are inconsistent with the study’s own megadeal figures. The percentage change and transaction counts are therefore more reliable measures for interpreting the release until the monetary units are clarified.

The increase in megadeals did not extend uniformly across transaction sizes.

Completed acquisitions valued between $1 billion and $10 billion declined to 45 in the third quarter from 48 in the second quarter.

Overall qualifying completed transactions also edged lower to 200 from 202.

This divergence suggests that large corporate combinations are driving much of the increase in transaction value, rather than a uniform acceleration across the acquisition market.

Acquirers underperform despite stronger deal activity

The most consequential finding for institutional investors concerns post-transaction market performance.

Of the 200 qualifying acquisitions completed in the third quarter, 121 buyers, or 60.5%, underperformed their relevant equity benchmarks.

Only 79 acquirers, representing 39.5%, outperformed. Global acquirers lagged their benchmarks by an average of 10.3 percentage points during the period, marking a second consecutive quarter of relative underperformance.

The regional results were uneven:

Region	Q3 completed deals	Relative performance
North America	109	-13.8 percentage points
Europe	37	-5.0 percentage points
Asia-Pacific	43	-18.7 percentage points

Asia-Pacific recorded the weakest relative performance, while European acquirers experienced a smaller shortfall.

North American buyers completed 109 transactions, compared with 103 during the preceding quarter.

These findings do not establish that acquisitions caused the underperformance. Share prices can also reflect interest rates, sector valuations, macroeconomic conditions and company-specific developments.

Nevertheless, the results challenge the assumption that rising M&A volumes necessarily signal improving investment outcomes.

Faster deal completion raises execution risks

The study also found that transaction timelines are shortening. Deals completed within 70 days of announcement accounted for 43% of third-quarter transactions, compared with 35% during the previous quarter.

Meanwhile, cross-sector acquisitions increased to 35% of completed transactions from 25%. The combination is significant because acquisitions involving unfamiliar industries, technology platforms or operating models can require more extensive due diligence and integration planning.

WTW’s Quarterly Deal Performance Monitor findings suggest that transaction speed has become an increasingly important characteristic of the current market.

For private equity sponsors, faster deal execution can create advantages in competitive auctions. However, accelerated timelines may also reduce the time available to assess earnings quality, customer concentration, financing assumptions and integration costs.

The risk becomes more consequential when acquisition prices incorporate ambitious growth forecasts or expected cost savings.

Large leveraged buyouts can be particularly sensitive to changes in financing costs because interest expenses directly affect cash flow available for debt repayment.

Private equity faces higher financing and exit hurdles

For private equity managers, the implications extend beyond acquisition activity.

Large strategic transactions can provide exit opportunities for buyout funds seeking to monetize portfolio companies. But higher borrowing costs and weaker buyer share-price performance can also complicate acquisition financing and negotiations over valuation.

The market is already producing substantial sponsor exits. In one recent transaction, Blackstone agreed to sell Clarion Events to Informa for £2.24 billion, illustrating how strategic buyers can provide liquidity for private equity-owned businesses.

At the same time, sponsors have increasingly used secondary-market transactions to generate liquidity when conventional exits are delayed.

PE NEWSWIRE previously reported on CVC’s $10 billion secondaries fundraising, reflecting investor demand for alternative ways to acquire private-market exposure and provide liquidity to existing fund investors.

These financing and liquidity considerations make the distinction between deal volume and investment performance particularly important.

A market dominated by large transactions may produce substantial advisory fees and headline deal values without necessarily improving exit conditions for every private equity portfolio.

Asia-Pacific records sharp relative underperformance

The regional findings also show that the global M&A recovery is uneven.

Asia-Pacific acquirers underperformed their regional benchmarks by 18.7 percentage points during the third quarter, the weakest result among the regions tracked.

The region recorded 43 qualifying completed transactions, down from 51 during the preceding quarter.

China was an exception in activity levels. Chinese buyers completed 21 transactions, compared with seven in the second quarter.

Europe recorded 37 completed transactions, continuing a decline in activity from 47 in the third quarter of 2025.

The results indicate that a rise in global megadeal activity does not necessarily correspond with stronger regional acquisition markets or improved returns for buyers.

What the M&A data means for 2027

WTW’s findings present two distinct signals for dealmakers entering the final quarter of 2026.

The first is that companies remain willing to pursue acquisitions large enough to transform their operations, market positions and technology capabilities.

The second is that investors have not consistently rewarded those transactions.

The 10.3-percentage-point average underperformance among third-quarter acquirers suggests that valuation discipline, financing structures and integration planning remain central to transaction outcomes.

For private equity investors, the critical measures will be whether strategic buyers continue providing attractive exit opportunities, whether acquisition financing remains available at acceptable costs and whether completed transactions generate the operating improvements used to justify their valuations.

The record number of megadeals demonstrates that the largest corporate buyers are still deploying capital.

The more important test is whether that capital produces returns that justify the acquisition prices.