| Abbreviation | Definition |
|---|---|
| ULTE | Ultimate Electronics, Inc. |
| ULTI | ltimate Software Group I |
| ULTI | Ultimate Software Group I |
| ULTK | Ultrak, Inc. |
| ULTPF | Ultra Petroleum Corporation |
| ULTR | Ultradata Systems, Inc. |
| ULU.V | Ultra Uranium Corporation |
| UMBF | U M B Financial Corporation |
| UMCI | United Medicorp, Inc. |
| UMEI | Universal Marketing & Entertainment, Inc. |
| UMMF | United Merchants & Manufacturing, Inc. |
| UMPQ | Umpqua Holdings Corporation |
| UMSI | Universal Medical Systems, Inc. |
| UNAM | Unico American Corporation |
| UNBJ | United National Bancorp of New Jersey |
| UNBO | U N B Corporation of Ohio (delisted; merged company is called Unizan Financial Corporation) |
| UNCA | Radio Unica Communication |
| UNCB | Uncle B's Bakery, Inc. |
| UNCB | Uncle B's Bakery, Incorporated (de-listed) |
| UNCB | Uncle B's Bakery, Incorporated (de-listed) |