| Abbreviation | Definition |
|---|---|
| AQIS.PK | Aquis Communications Group, Inc. |
| AQLA | Aquila Biopharmaceuticals, Inc. |
| AQRO | Aqua Pro Corporation |
| AQSE | Aquasearch, Inc. |
| AQUA | Aquaculture Production Technologies |
| ARBA | Ariba, Inc. |
| ARBX | Air Brook Airport Express |
| ARCAF | Arcadis, N. V. |
| ARCC | Allied Riser Communications Company |
| ARCI | Appliance Recycling Centers of America, Inc. |
| ARCT | Arcturus Therapeutics Holdings Inc |
| ARCX | Affiliated Resources Corporation |
| ARDI | @Road, Inc. |
| ARDM | Aradigm Corporation |
| ARDNA | Arden Group, Inc. Class A |
| AREA | Area Bancshares Corporation |
| AREC | Americom Resources Corporation |
| AREE | Arete Industries, Inc. |
| AREM | AremisSoft Corporation |
| ARET | Ameriresource Technology, Inc. |