| Abbreviation | Definition |
|---|---|
| HDRN | Hadron, Inc. |
| HDSG | Hudsons Grill America, Inc. |
| HDSN | Hudson Technologies, Inc. |
| HDTV | Spatialight, Inc. |
| HDVS | H. D. Vest, Inc. |
| HDWY | Headway Corporate Resources, Inc. |
| HEAL | Healthwatch, Inc. |
| HEAR | HearMe, Inc. |
| HEARZ | Hearme (delisted) |
| HECO | Hallwood Energy Corporation |
| HECOP | Hallwood Energy Corporation Preferred |
| HECPV | Hallwood Consolidated Resources |
| HEII | H E I, Inc. |
| HELE | Helen of Troy, LTD. |
| HELO | Hello Direct, Inc. |
| HELP | Helpmate Robotics, Inc. |
| HELPW | Helpmate Robotics, Inc. Warrants |
| HELX | Helix Technology Corporation |
| HEMA | Hemacare Corporation |
| HENL | Henley Healthcare, Inc. |