| Abbreviation | Definition |
|---|---|
| CONC | Contour Energy Company |
| CONCP | Contour Energy Company Preferred |
| CONE | Carrier 1 International |
| CONV | Convergent Communications |
| COOK | California Culinary Academy (delisted) |
| COOL | Cyberian Outpost, Inc. |
| COOP | Cooperative Bankshares |
| COPE | Cope, Inc. |
| COPI | Crescent Operating, Inc. |
| COPY | Copytele, Inc. |
| CORE | Core, Inc. |
| CORE | Core, Incorporated |
| CORL | Corel Corporation |
| CORR | C O R Therapeutics, Inc. |
| CORS | Corus Bankshares, Inc. |
| CORX | Cortex Pharmaceutical, Inc. |
| COSI | Computer Outsourcing Services, Inc. |
| COSN | Cosine Communications, Inc. |
| COST | Costco Wholesale Corporation |
| COTT | Cott Corporation of Quebec |