William O'Neil Securities
Financial ServicesMassachusetts, United States11-50 Employees
William O'Neil Securities, based in Boston, Massachusetts, operates as a broker-dealer with a buy-side trading mindset designed to act as an extension of its clients' teams. Its trading desk relationships are positioned beyond mere order execution, supported by seasoned sales traders and leadership with a long history in a family of investment companies. Traders are trained in institutional investment research through the PANARAY platform, which ties them to the O'Neil Methodology and buy-side processes while offering objective access to equity markets. This cross-training aims to provide an additional perspective on order flow while preserving agency-only objectivity and cost-efficient access to markets. Founded in 1963, the firm focuses on institutional and other buy-side clients, and in May 2026 it announced the appointment of Brian Williamson as managing director of electronic trading to broaden its electronic trading capabilities.