OP began operations in March, 2005 and is majority owned by the executive partners. The firm manages six types of equity portfolios: global (including global ex-US), global equity income, global smaller companies, European, Japanese and emerging markets. It also has a manager of equity managers strategy.

OP manages equity portfolios with a distinctive approach: a limited number of holdings, long-only, no leverage, value-focussed, diversified, index-ignorant and suspicious of short-termism.