| Abbreviation | Definition |
|---|---|
| DDN | Dynamex, Inc. |
| DDN | Dynamex, Incorporated |
| DGV | Digital Lava, Inc. |
| DHC | Danielson Holding Corporation |
| DIA | Diamonds Trust |
| DII | Decorator Industries, Inc. |
| DIO | Diodes, Inc. |
| DIT | Amcon Distributing Company |
| DLI | Del Labs, Inc. |
| DLK | Datalink Net, Inc. |
| DMC | Dairy Mart Convenience Stores |
| DMCB | Dairy Mart Convenience Stores Class B |
| DMI | Depomed, Inc. |
| DMMA | Dia Met Minerals, Ltd. Class A (delisted) |
| DMMB | Dia Met Minerals, Ltd. Class B (delisted) |
| DOC | Medical Advisory Systems, Inc. |
| DOR | Endorex Corporation |
| DPW | Digital Power Corporation |
| DRA | Duraswitch Industries, Inc. |
| DRH | Driver Harris Company |