| Abbreviation | Definition |
|---|---|
| MWGP | Midwest Grain Products, Inc. |
| MWHS | Micro Warehouse, Inc. |
| MWHX | Markwest Hydrocarbon, Inc. |
| MWMD | M W Medical |
| MWPSL | MidAmerican Energy Company |
| MWPSM | MidAmerican Energy Company |
| MWPSP | MidAmerican Energy Company Preferred |
| MWRK | Mothers Work, Inc. |
| MWSI | Mercury Waste Solutions, Inc. |
| MXBIF | M F C Bancorp, LTD. |
| MXICY | Macronix International Company, LTD. |
| MXIM | Maxim Integrated Products, Inc. |
| MXIP | MAX Internet Communications |
| MXIYZ | Macronix International Company |
| MXMX | Media X Corporation |
| MXTR | Maxtor Corporation |
| MXWL | Maxwell Technologies, Inc. |
| MYGN | Myriad Genetics, Inc. |
| MYIQ | Edulink, Inc. |
| MYPT | Mupoints.Com, Inc. |