O
- Oasis Asset Management
- Ocean Equities Ltd
- Oceanic Asset Management Pty
- Och-Ziff Capital Management Group LLC
- Octa Phillip
- Odey Asset Management (OAM)
- Old Mutual South Africa Trust plc
- Oleg Deripaska
- Onexim Group
- Ongpin Group
- Ontario Teachers Pension Plan Board
- OP-Delta Mutual Fund
- Oppenheimer Funds
- ORGAMAN
- Orchard Capital Group
- Origo Sino-India
- Ospraie
- Owen Hegarty
- OZ Management LP
