A working directory of the firms, global networks, professional bodies, and standard-setters that make up the profession — and, increasingly, the capital now buying it outright. This is still a first pass, built to be appended, not a finished census.
In December 2025, OpenAI took an equity stake in Thrive Holdings — a Josh Kushner-founded spinout of Thrive Capital that runs less like a startup and more like a private equity firm for the AI era — and agreed to embed its own staff inside Thrive's portfolio companies. In August 2026, Thrive raised $2 billion at a $12 billion valuation from SoftBank, D1 Capital Partners, and Altimeter Capital: its first outside capital ever. Thrive's "Current" platform already spans 50+ accounting firms and 2,000+ professionals; its TaxAI tool has processed 7,000+ returns at 98% accuracy, cutting preparation time by more than 30%. Part of the new raise funds a third vertical entirely — regulatory services for physical infrastructure.
Thrive isn't alone. Private equity has been buying up the accounting profession for five years — Blackstone, TowerBrook, New Mountain Capital, Hellman & Friedman, and Charlesbank all now hold stakes in top-20 US firms. What's new is a frontier AI lab joining that list, with its own engineers on the ground inside the firms it now partly owns. The Capital Platforms tier below tracks both threads.
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