Bain's 2026 M&A Report: What the Great Rebound Means for Boutique Advisors

Bain & Company's 2026 M&A Report documents what many dealmakers felt but struggled to quantify: 2025 was a genuine rebound year. Global deal value reached an estimated $4.9 trillion — up 40 percent in value and 7 percent in volume — making it the second-highest year on record. After two years of market caution driven by rising rates, regulatory headwinds, and valuation dislocation, the deals came back.

For boutique advisory firms, the headline number matters less than what was underneath it. Bain found that megadeals — transactions exceeding $5 billion — accounted for more than 73 percent of incremental deal value. The volume story, by contrast, was driven by midmarket activity: more transactions at lower sizes, across a broader range of sectors. That's the space where boutique advisors compete, and 2025 validated it as structurally healthy.

Scope deals dominated — and that changes the advisory brief

One of Bain's most significant findings is that scope deals — acquisitions driven by revenue growth rather than cost synergies — accounted for 60 percent of large transactions, making 2025 the biggest year on record for this category. Scope deals are harder to underwrite than efficiency plays. They require advisors to articulate a credible growth thesis, map customer overlap, and defend revenue projections under scrutiny.

For boutique advisors, this is a strategic signal. Clients pursuing scope-driven acquisitions need advisors who understand their market positioning deeply — not just their financials. The firms that won mandates in 2025 weren't just the ones with the best process; they were the ones who could articulate a compelling strategic rationale for a deal that might look expensive on traditional multiples.

AI adoption in M&A doubled — and early movers are pulling ahead

Bain reports that AI adoption among M&A practitioners more than doubled in 2025, reaching 45 percent. More importantly, early adopters aren't just using AI as a productivity tool — they're using it across the deal cycle, including due diligence, transaction execution, and post-close integration. Bain explicitly links early AI adoption to 'concrete advantage' in dealmaking.

Early AI adopters aren't just faster — they're capturing better information and moving through deal phases that used to take weeks in days.

For boutique advisors still running manual due diligence workflows and assembling information memoranda in PowerPoint, this data point is a prompt for urgency. The gap between firms using AI tools consistently and those that aren't is already visible in deal timelines and output quality — and it will widen.

80 percent expect more deals in 2026 — but capital allocation to M&A hit a 30-year low

Here's the paradox Bain surfaces: 80 percent of M&A executives expect to sustain or increase deal activity in 2026, yet the proportion of corporate capital actually allocated to M&A hit its lowest level in 30 years relative to available capital. The implication is a market with strong intent but disciplined deployment — more mandates being scoped, more processes being run, but tighter deal scrutiny and less automatic approval at the top of organisations.

For boutique advisors, this means a busier market in terms of origination work but one where transaction certainty requires better preparation. Clients need advisors who can run tight, credible processes that survive the increased scrutiny that boards and investment committees are applying to deal decisions in 2026.

Source: Global M&A Poised to Sustain Momentum in 2026 After Great Rebound — Bain & Company.