Sorai Diligence Index 2026

Average sign-to-close time

191 days

BCG reported an average of 191 days from announcement to close for deals above $2 billion in its 2024 M&A report.

Deals missing announced close timing

~40%

BCG said about 40% of transactions took longer to close than announced at signing.

Organizations using GenAI in M&A workflows

86%

Deloitte reported that 86% of surveyed organizations have integrated GenAI into their M&A workflows.

Security as the leading GenAI concern

67%

Deloitte identified data security as the top concern for GenAI adoption in M&A at 67% of surveyed organizations.

What the index measures

The Sorai Diligence Index 2026 is built to answer a simple operating question: where does diligence lose time and confidence before it reaches the investment committee, lender, or final negotiating table?

Rather than acting like a vanity trend report, the index turns market signals into a practical benchmark. It combines public research with a process scorecard so buyers and advisors can compare their current workflow against a more decision-grade operating model.

• Document readiness: how cleanly the file flow starts and how quickly the team reaches usable inputs.
• Cross-workstream visibility: whether financial, tax, and legal findings can be compared inside one live record.
• Evidence integrity: whether findings stay linked to source material, reviewer ownership, and change history.
• Decision synthesis: whether managers and partners can review the live story before the final memo sprint.
• AI governance: whether automation is bounded by permissions, review controls, and source-verification discipline.

Timeline signal: large deals are still taking too long to close

The headline timeline problem has not gone away. Boston Consulting Group reported that deals above $2 billion averaged 191 days from announcement to close in 2024, and roughly 40% of announced deals missed their original close timing.

That matters because long diligence cycles are rarely just scheduling problems. They usually reflect friction across document intake, specialist review, open-issue convergence, and late-stage synthesis for decision-makers.

• Longer close cycles increase the cost of delay for buyers, management teams, and advisors.
• Delayed transactions force more rework because facts, priorities, and management narratives keep shifting.
• The later the synthesis starts, the more likely the team is rebuilding context from spreadsheets, PDFs, and comments.
• Timeline compression depends on workflow design, not just more analyst hours.

Bottleneck signal: most delay is operational before it is analytical

The index treats diligence slowdown as an operating-model issue first. In practice, teams lose time because the work lives in too many places and converges too late.

That is why the same bottlenecks show up repeatedly across mid-market and large-cap processes, regardless of whether the team has strong technical talent.

• Late or messy file delivery keeps specialists from starting with the right evidence set.
• Financial, tax, and legal workstreams often run in separate tools with weak issue convergence.
• The highest-value questions are not always prioritized early enough for pre-LOI or week-one review.
• Draft findings lose force when they are detached from source support and reviewer history.
• Teams often restart from scratch between early screening, post-LOI diligence, and committee output.

AI signal: adoption is real, but governance separates signal from theater

AI adoption in M&A is no longer hypothetical. Deloitte reported that 86% of surveyed organizations already use GenAI somewhere in their M&A workflow, which means the market has moved from experimentation to operating-model choices.

The harder question is not whether firms use AI. It is whether they use it inside a process that preserves evidence, reviewer judgment, and defensibility. Deloitte's security signal and McKinsey's repeated governance warnings both point to the same conclusion: speed without control does not create decision-grade diligence.

• Use AI first for intake, extraction, first-pass classification, and issue triage.
• Keep material conclusions inside a human-reviewed workflow with source linkage.
• Do not mistake a fast summary for a defensible diligence answer.
• Treat permissions, audit history, and model boundaries as first-order design requirements.
• Benchmark AI maturity by workflow quality, not by demo novelty.

The Sorai five-part scorecard

To make the report usable, Sorai scores diligence maturity across five equal dimensions. Teams do not need a perfect score to improve, but they do need clarity on where delay and weak confidence actually originate.

The most common pattern is uneven maturity: one workstream becomes highly efficient while the shared evidence chain and final synthesis remain fragile. The index is designed to surface that mismatch.

• 20 points for document readiness: controlled intake, clean indexing, and fewer false starts.
• 20 points for cross-workstream visibility: one live issue record instead of fragmented specialist outputs.
• 20 points for evidence integrity: every material conclusion tied back to documents and reviewer history.
• 20 points for decision synthesis: partner, IC, and lender review built while the work is live.
• 20 points for AI governance: bounded automation, source verification, and clear ownership of outputs.

What teams should do next

The practical use of the index is straightforward: benchmark the current process, identify the weak link, and fix the operating discipline before adding more complexity.

For marketing and domain-authority work, the report also gives Sorai a public benchmark asset that can be cited by legal press, private markets writers, advisors, and partner firms without forcing them to cite a product page directly.

• Use the report in outreach as a benchmark asset, not as a disguised sales deck.
• Point contextual backlinks to the most relevant pillar or workflow page from bylined guest articles.
• Refresh the index quarterly as new public timeline and AI-adoption signals emerge.
• Pair the report with downloadable checklists and case-study proof for stronger editorial pickup.
• Track which sections earn citations so future research pieces go deeper where the market already responds.

Assets & next steps

Sources cited

1. 1.
   Boston Consulting Group — The 2024 M&A Report: Deals Are Taking Longer to Close. How to Respond.

   Used for the 191-day sign-to-close benchmark and the share of deals that missed announced timing.

2. 2.
   Boston Consulting Group — Evaluating Pricing in Due Diligence for Value Creation in Private Equity

   Used for the broader point that focused diligence can surface economically meaningful findings on a compressed timeline.

3. 3.
   Deloitte — 2025 M&A Generative AI Study

   Used for adoption and concern signals cited in the report, including 86% workflow integration and 67% data-security concern.

4. 4.
   McKinsey & Company — Gen AI: Opportunities in M&A

   Used for the argument that GenAI can accelerate diligence and negotiation only when wrapped in stronger process design and guardrails.

5. 5.
   McKinsey & Company — Harnessing the power of gen AI in private markets

   Used for the distinction between fast AI output and investment-grade completeness or realism.

6. 6.
   Bain & Company — Looking Ahead to 2025: Preparing for What Comes Next

   Used for the framing that value capture begins with faster, deeper, and more focused diligence rather than disconnected specialist work.

What is the Sorai Diligence Index 2026?

It is Sorai's benchmark report for M&A diligence timelines, operating bottlenecks, and AI adoption. The market facts come from named public sources, while the scorecard and operating framework are Sorai's synthesis.

Is this report based on a proprietary survey?

No. It is a benchmark synthesis built from public 2024-2026 market research plus Sorai's operating-model framework for evaluating diligence maturity.

How should firms use the report?

Use it to benchmark current workflow maturity, support partner or committee discussions about process redesign, and provide citation-ready context in outreach or bylined articles.

Can media or partners cite this report?

Yes. Sorai encourages citation with a direct link to the canonical report URL so readers can review the benchmark framework and named source list in full context.