| Abbreviation | Definition |
|---|---|
| APRDP | Alabama Power Company Preferred |
| APROZ | America First- Apartment Investors |
| APRPT | Alabama Power Company |
| APRS | Approps Technology, Inc. |
| APSB | American Pacific State Bank |
| APSG | Applied Signal Technology, Inc. |
| APTB | AlphaTrade.com |
| APTD | Alpha Pro Technology, LTD. |
| APTG.PK | Applied Technologies, Inc. |
| APTH.PK | American Power Technology, Inc. |
| APTL.PK | Alaska Power and Telephone Company |
| APTM | Aptimus, Inc. |
| APUH | American Public Holdings, Inc. |
| APUX | Anchor Pacific Underwriters |
| APWR | Astropower, Inc. |
| AQBC | Aqua Vie Beverage Corporation |
| AQBEF | Aqua 1 Beverage Company, Inc. |
| AQCB | Aqua Clara Bottling & Distributors |
| AQCI | Aquatic Cellulose International |
| AQCR | Aqua Care Systems, Inc. |