| Abbreviation | Definition |
|---|---|
| ACEC | Ace Communications Corporation |
| ACEE | Acme Electric Corporation |
| ACEI | American Champion Entertainment, Inc. |
| ACEIW | American Champion Entertainment, Inc. Warrants |
| ACEL | AlfaCell Corporation |
| ACET | Aceto Corporation |
| ACFI | American Community Financial, Inc. |
| ACFN | Acorn Factor, Inc. |
| ACFU | Air Cargo Facilities Income Fund |
| ACFX | AtlasCapital Financial Services, LTD. |
| ACHC | American Capital Holdings, Inc. |
| ACHI | American Country Holdings, Inc. |
| ACHIW | American Country Holdings, Inc. Warrants |
| ACII | ACI Asset Management, Inc (formerly AMCI International, Inc.) (delisted) |
| ACIT | A C I Telecentrics, Inc. |
| ACLE | Accel International Corporation |
| ACLM | Allis-Chalmers Corporation |
| ACLNF | A. C. L. N. Limited |
| ACLR | Accent Color Sciences, Inc. |
| ACLYE | Accelr8 Technology Corporation (delisted) |