| Abbreviation | Definition |
|---|---|
| AMO | After Market Order |
| AMOS | AMEX (American Stock Exchange) Options Switching System |
| AMS | Automatic order Matching and execution System |
| AMV | Approximate Market Value |
| ANTE | Amex New Trading Environment |
| AODB | American Stock Exchange Options |
| AOM | Australian Options Market |
| AOT | Amsterdam Options Traders |
| APA | Approved Publication Arrangement |
| APCIMS | Association of Private Client Investment Managers and Stockbrokers |
| APE | Auckland Peering Exchange |
| API | As Per Instructions |
| APIC | Additional Paid In Capital |
| APIR | Asia Pacific Investment Register |
| APO | Advanced Planning Optimizer |
| APOT | Asset Protection Offshore Trust |
| APT | Arbitrage Pricing Theory |
| APT | Asset Protection Trust |
| APT | Automated Pit Trading system |
| APTF | Arabian Programmed Trading Fund |