It is the world’s largest expert network, with over 900,000 freelance consultants. GLG's experts include asset managers, investors, consultants, physicians, scientists, engineers, lawyers, senior current and former c-level executives, and former government members. GLG's clients include strategy consulting corporations, hedge funds, private equity firms, professional service firms, and non-profit organizations.

The firm was founded in 1998 and has been backed by private equity firms Silver Lake Partners, Bessemer Venture Partners, and SFW Capital Partners. GLG is headquartered in New York City, with offices in 22 cities in 12 countries. 

The expert network business model has drawn scrutiny for concerns relating to adherence to disclosure rules and insider trading within the investment industry. GLG's policies include prohibitions against consultants sharing any nonpublic information about their employer or any public company, violating any ethical or legal restrictions relevant to consultants, or violating any laws.

According to en.wikipedia