US M&A Value Explodes in October 2025: Megadeals Lead While Private Equity Holds Mid-Market

The EY “US M&A activity insights: October 2025” report reveals a sharp acceleration in deal value across U.S. M&A markets. October’s total deal value was up some 146.5% versus October 2024, with deals above US$1 billion seeing particularly strong expansion—value up ~203% and volume up ~70% YoY. [1] These gains were supported by easing financing conditions—rate cuts by the Federal Reserve on September 17 and October 29, 2025—and narrowing valuation gaps between buyers and sellers. [1]

Private equity (PE), while still active, saw its share of high-end (>US$100 million) deals fall sharply in October—40.4% of value vs ~59.2% in September—indicating that corporates were increasingly dominating large transactions. [1] PE’s performance in October was marked by a dip from September’s peak in value but remained among the strongest months in 2025, especially for mid-market and minority investments. [1]

Sectors leading the charge are technology and life sciences, including AI infrastructure, digital capabilities, and resilient franchises in the consumer and energy sectors. Horizontal integration was also notable in mature sectors like banking, utilities, and technology, as corporations seek scale and cost synergies. [1]

FactSet data adds granularity: though overall deal announcements fell slightly (~3.3%) in October vs September, aggregate spending rose, in part due to several large headline deals. [9] Major transactions included Aligned Data Centers (US$40B), Skyworks-Qorvo (~US$9.7B), Occidental Chemical (Berkshire Hathaway’s ~US$9.7B acquisition), Thermo Fisher-Clario (~US$9.4B), and Huntington Bancshares’ acquisition of Cadence Bank (~US$7.4B). [9]

Global data aligns: October recorded the highest number of $10B+ deals since mid-2022, with eight such large transactions announced globally, several in the U.S. [2] Meanwhile, global PE & VC deal value jumped ~49% YoY in October to roughly US$111.44B, even as deal count declined, consistent with the observed skew toward large transactions. [8]

Looking ahead, EY forecasts U.S. deals over US$100 million will rise ~9% in 2025 and ~3% in 2026. Corporate M&A volume is expected to grow ~10% in 2025 and ~3% in 2026; PE deal volume ~8% in 2025 with ~5% growth in 2026. Deal value is expected to gain further momentum due to increasing share of large transformative deals. [5][6]

Strategic implications include: corporates must consider whether to push early in this upswing or risk paying premium later; PE investors face mid-market sweet spots and need to sharpen value creation to compete with corporates; sector focus should remain on technology, AI infrastructure, life sciences, utilities, and horizontal consolidation; attention to regulatory risk as deal sizes invite scrutiny.

Open questions include: Will interest rate stability (or further cuts) sustain current valuations? Can regulatory regimes (anticompetition, foreign investment) accommodate more megadeals? How will medium and smaller deals fare if markets fixate on headline transactions? And what stress tests exist for sectors where integration risk is high (utilities, industrials)?