Grantham, Mayo, Van Otterloo & Co. LLC (GMO) is a private investment management firm headquartered in Boston, Massachusetts. Founded in 1977 by Jeremy Grantham, Dick Mayo, and Eijk van Otterloo, GMO offers a range of investment strategies across various asset classes, including equities, fixed income, and alternatives. The firm is known for its long-term, valuation-based investment philosophy, emphasizing disciplined, research-driven approaches to asset management. ​