Chatham Financial Builds Capital Markets Tools with OpenAI Codex

OpenAI published a customer case study on October 2, 2026, describing how Chatham Financial, a capital markets advisory firm, uses OpenAI’s Codex and GPT-5.6 models across its advisory workflows, including a trade validation application the firm says reduced review time from approximately 30 minutes to under four. The case study lists Chatham as a small and medium-sized business in the finance industry in North America, with ChatGPT, Codex, and the OpenAI API as the products in use.

The firm works with clients on complex capital markets decisions. According to the case study, Chatham uses Codex to build internal and client-facing tools and GPT-5.6 to power AI features, work that spans employee-built applications, its next-generation capital markets operating system, Chatham Onyx, and its reengineering consulting service, Process Zero. Chief Executive Officer Matt Henry said the firm begins with the outcome it wants, pinpoints where judgment matters, and then designs how to deliver that outcome with the capabilities currently available.

Through Process Zero, Chatham reengineers workflows around outcomes. For each workflow, the firm establishes the minimum inputs and evidence needed, fixes where…