| Abbreviation | Definition |
|---|---|
| TXSUM | Texas Utilities Electric Company (delisted) |
| TXSUO | Texas Utilities Electric Company (delisted) |
| TXSUP | Texas Utilities Electric Company (delisted) |
| TXUI | Texas United Bancshares, Inc. |
| TYCB | alvin B Taylor Banking |
| TYCB | Calvin B Taylor Banking |
| TYCO | Tayco Developments, Inc. |
| TYME | TimeOne, Inc. |
| TZIX | Trizetto Group, Inc. |
| TZOO | Travelzoo, Inc. |
| UACA | Union Acceptance Corporation |
| UAIRA | U S Aircraft Corporation |
| UAMY | United States Antimony |
| UAMY | United States Antimony Corporation |
| UASG | USAssurance Group, Inc. |
| UASG | USAssurance Group, Incorporated (de-listed) |
| UASG | USAssurance Group, Incorporated (de-listed) |
| UAXS | Universal Access, Inc. |
| UAXS | Universal Access, Incorporated (de-listed) |
| UAXS | Universal Access, Incorporated (de-listed) |