Who audits public companies 2026
The audit market is shifting. Firm consolidations, SPAC growth and evolving client demands are redrawing competitive lines across every exchange, filer category and industry sector. Our March 2026 report gives you a complete picture of who audits public companies right now — across 230 audit firms and 6,286 SEC registrants.
Whether you're benchmarking your firm's position, identifying new business targets or tracking how your competitors are growing their client base, this is the data that tells the full story.
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The Big Four tighten their grip on the largest companies
The Big Four audit approximately 90% of large accelerated filers but their dominance drops sharply further down the market, where mid-tier and other firms hold the majority.
Market share is moving and not always where you'd expect
Deloitte grew to 926 registrant clients and Baker Tilly broke into the top 10 for the first time off the back of recent merger activity.
SPACs are back on the radar
SPACs now represent 4% of total registrants, up from 2.4% in the prior report, and the Big Four are entirely absent from the segment, leaving mid-tier and smaller firms to compete for a growing pool of engagements.
Industry concentration reveals where auditor competition is fiercest
The Big Four audit 59% of energy and transportation companies but just 43% in trade and services — knowing where the lines fall in your target sectors helps you prospect smarter and pitch with confidence.
Who audits public companies 2026
Download the full report to see market share breakdowns by exchange, jurisdiction, filer status, US region and industry.