| ACAD | ACADIA Pharmaceuticals Inc. | 14.19 | Stock | Biotechnology | NGM |
| ACI | Arch Coal Inc. | 5.31 | Stock | Industrial Metals & Minerals | NYQ |
| ACN | Accenture plc | 82.22 | Stock | Information Technology Services | NYQ |
| ATVI | Activision Blizzard, Inc. | 15.61 | Stock | Multimedia & Graphics Software | NMS |
| ACAS | American Capital, Ltd. | 13.82 | Stock | Asset Management | NMS |
| ACE | ACE Limited | 89.78 | Stock | Property & Casualty Insurance | NYQ |
| ACHN | Achillion Pharmaceuticals, Inc. | 7.58 | Stock | Biotechnology | NMS |
| ACOR | Acorda Therapeutics, Inc. | 32.67 | Stock | Biotechnology | NMS |
| ACTG | Acacia Research Corporation | 23.53 | Stock | Research Services | NMS |
| ACUR | Acura Pharmaceuticals, Inc. | 2.37 | Stock | Drug Delivery | NCM |
| ARAY | Accuray Incorporated | 5.19 | Stock | Medical Appliances & Equipment | NMS |
| ACTC | Advanced Cell Technology Inc. | 0.07 | Stock | Biotechnology | OBB |
| AH | Accretive Health, Inc. | 11.09 | Stock | Management Services | NYQ |
| ACLS | Axcelis Technologies Inc. | 1.59 | Stock | Semiconductor Equipment & Materials | NMS |
| ACET | Aceto Corp. | 11.86 | Stock | Chemicals - Major Diversified | NMS |
| ACRX | AcelRx Pharmaceuticals, Inc. | 7.86 | Stock | Drug Manufacturers - Major | NGM |
| ACO | AMCOL International Corporation | 31.54 | Stock | Industrial Metals & Minerals | NYQ |
| ACH | Aluminum Corporation Of China Limited | 9.92 | Stock | Aluminum | NYQ |
| ACT | Actavis, Inc. | 127.23 | Stock | Drugs - Generic | NYQ |
| ACIW | ACI Worldwide, Inc. | 45.55 | Stock | Technical & System Software | NMS |