| Abbreviation | Definition |
|---|---|
| ARE | Aecon Group Inc. |
| ARE | Aecon Group Incorporated |
| ARF | Armtec Infrastructure Income Fund |
| ARG | Amerigo Resources Ltd. |
| ARL | Africo Resources Ltd. |
| ARX | ARC Resources Ltd. |
| ARZ | Aurizon Mines Ltd. |
| ASC | AIC Global Financial Split Corporation |
| ASF | Acuity Small Cap Corporation |
| ATA | ATS Automation Tooling Systems Inc. |
| ATA | ATS Automation Tooling Systems Incorporated |
| ATB | Atrium Innovations Inc. |
| ATB | Atrium Innovations Incorporated |
| ATD | Alimentation Couche-Tard Inc. |
| ATD | Alimentation Couche-Tard Incorporated |
| ATH | Athabasca Oil Sands Corporation |
| ATN | Atna Resources Ltd. |
| ATN | Atna Resources, LTD. |
| ATP | Atlantic Power Corporation |
| ATQ | Adeptron Technologies Corporation |