| Abbreviation | Definition |
|---|---|
| SYKE | Sykes Enterprises, Incorporated |
| SYLN | Sylvan, Inc. |
| SYLN | Sylvan, Incorporated (de-listed) |
| SYLN | Sylvan, Incorporated (de-listed) |
| SYMBA | Symbollon Corporation |
| SYMC | Symantec Corporation |
| SYME | Synergy Media, Inc. |
| SYMM | Symmetricom, Inc. |
| SYMX | Symix Systems, Inc. |
| SYNC | Synalloy Corporation |
| SYNL | Syntellect, Inc. |
| SYNM | Syntroleum Corporation |
| SYNT | Syntel, Inc. |
| SYNX | Sync Research, Inc. |
| SYPM | Symposium Corporation |
| SYPR | Sypris Solutions, Inc., of Delaware |
| SYPR | Sypris Solutions, Incorporated, of Delaware |
| SYSC | Smart Tech, Inc. |
| SYSC | Smart Tech, Incorporated (de-listed) |
| SYSC | Smart Tech, Incorporated (de-listed) |