Global M&A activity in the first half of 2026 rose 44% year-over-year to USD 3.16tn, shrugging off war in the Middle East, volatile energy prices and rising financing costs.

The total marked the strongest first half on record.

Beneath the headline surge, however, the market remained polarized. While deal values rose sharply, deal count contracted 3%, with a small number of transformative transactions carrying an outsized share of activity.

Megadeals valued at USD 10bn or more reached a record USD 1.32tn across 48 transactions, accounting for 42% of total global M&A volume. Turbo-charged AI-linked valuations drove a record six gigadeals – valued at USD 50bn-plus – in 1H26.

Large-cap corporates, whose strong balance sheets make them less sensitive to market gyrations and rising borrowing costs, led the way.

By contrast, activity in the middle market – deals between USD 250m and USD 1bn – remained tepid. While megadeal volume more than doubled, midmarket volume rose just 16% to USD 404.5bn.