| Osaic Wealth, Inc. | Scottsdale, AZ | $234.86B | — |
| Olive Street Investment Advisers, LLC | St. Louis, MO | $203.76B | — |
| Oaktree Capital Management, L.P. | Los Angeles, CA | $183.29B | 283 |
| Onedigital Investment Advisors LLC | Overland Park, KS | $155.41B | — |
| Oak Hill Advisors, L.P. | New York, NY | $100.72B | 94 |
| Oc Investment Management LP | Miami, FL | $75.93B | 1 |
| Orion Portfolio Solutions, LLC | Omaha, NE | $64.84B | — |
| Oppenheimer & Co. Inc. | New York, NY | $36.71B | — |
| Octagon Credit Investors, LLC | New York, NY | $35.05B | 59 |
| Onex Credit Partners, LLC | Englewood Cliffs, NJ | $30.14B | 68 |
| Oneamerica Asset Management, LLC | Indianapolis, IN | $24.42B | — |
| Oxford Financial Group, Ltd. LLC | Carmel, IN | $23.33B | 48 |
| Ottawa Avenue Private Capital, LLC | Grand Rapids, MI | $22.95B | 28 |
| Onex Partners Manager LP | Toronto | $22.47B | 35 |
| Oppenheimer Asset Management Inc. | New York, NY | $21.33B | 3 |
| Orbimed Advisors LLC | New York, NY | $20.61B | 23 |
| Offit Capital Advisors LLC | New York, NY | $20.6B | 123 |
| O'Shaughnessy Asset Management, LLC | Stamford, CT | $19.78B | — |
| Omers Infrastructure US Limited | New York, NY | $17.83B | 3 |
| O'Connor Alternative Investments, LLC | New York, NY | $16.37B | 13 |
| One Queen Capital Inc. | Toronto, Ontario | $15.9B | 5 |
| Oep Capital Advisors, L.P. | New York, NY | $15.73B | 34 |
| Osaic Advisory Services, LLC | Atlanta, GA | $15.48B | — |
| Oaktree Fund Advisors, LLC | Los Angeles, CA | $14.1B | — |
| Oak Hill Capital Management, LLC | New York, NY | $13.93B | 35 |
| Oasis Capital Partners (texas) Inc. | Austin, TX | $12.4B | 9 |
| One William Street Capital Management, LP. | New York, NY | $11.3B | 8 |
| Orchard Global Asset Management LLP | London | $11.28B | 8 |
| Openarc Corporate Advisory, LLC | Atlanta, GA | $10.09B | — |
| One Investment Management US LLC | New York, NY | $10.08B | 4 |
| One Rock Capital Partners, LLC | New York, NY | $9.7B | 17 |
| Orix Advisers, LLC | New York, NY | $9.63B | 15 |
| Orgel Wealth Management, LLC | Altoona, WI | $9.55B | — |
| Olympus Advisors, LLC | Stamford, CT | $9.25B | 12 |
| Ogam, LP | Houston, TX | $8.69B | 4 |
| One Capital Management, LLC | Westlake Village, CA | $8.53B | — |
| Overlook Investments L.P. | Georgetown | $8.09B | 2 |
| Overlook Investments Limited | Hong Kong | $8.09B | — |
| Orion Resource Partners (USA), LP | New York, NY | $7.91B | 14 |
| Odyssey Investment Partners, LLC | New York, NY | $7.85B | 16 |
| Osterweis Capital Management LLC | San Francisco, CA | $7.5B | — |
| One Madison Group LLC | New York, NY | $7.02B | 4 |
| Oceansound Partners, LP | New York, NY | $6.95B | 27 |
| Omnicap Group LLC | El Segundo, CA | $6.51B | — |
| Osaic Institutions, Inc. | Meriden, CT | $6.49B | — |
| Octopus Renewables Ltd. | London | $6.4B | 3 |
| Org Portfolio Management LLC | Beachwood, OH | $6.38B | 5 |
| Obra Capital Management, LLC. | New York, NY | $5.75B | 12 |
| Oasis Investment Strategies LLC | Chicago, IL | $5.73B | — |
| Oberweis Asset Management Inc | Lisle, IL | $5.06B | 1 |