| Abbreviation | Definition |
|---|---|
| ACN | Acuson Corporation |
| ACO | AMCOL International Corporation |
| ACP | American Real Estate Partners |
| ACR | American Retirement Corporation |
| ACS | Affiliated Computer Services, Inc. |
| ACV | Alberto Culver Company |
| ACVA | Alberto Culver Company Class A |
| ACX | ACX Technologies (now Graphic Packaging International Corporation) |
| AD | ADVO, Inc. |
| ADC | Agree Realty Corporation |
| ADF | ACM Managed Dealer Income Fund |
| ADI | Analog Devices, Inc. |
| ADM | Archer Daniels Midland Company |
| ADP | Allied Products Corporation of Delaware |
| ADV | Advest Group, Inc. |
| ADX | Adams Express Company |
| AEC | Associated Estates Realty Corporation |
| AED | Banco de A Edwards |
| AEE | Ameren Corporation |
| AEG | Aegon, N. V. |