| HOLOW | MicroCloud Hologram Inc. | Technology | $8.7M | — | 0 |
| MMTIF | Micromem Technologies Inc. | Technology | $7.9M | — | 0 |
| MU | Micron Technology, Inc. | Technology | $1.2T | — | 0 |
| MCRP | Micropolis AI Robotics | Industrials | $27.0M | — | 0 |
| MSFT | Microsoft Corporation | Technology | $3.7T | — | 0 |
| MVST | Microvast Holdings, Inc. | Industrials | $229M | — | 0 |
| MVIS | MicroVision, Inc. | Technology | $38.3M | — | 0 |
| MWC | Micware Co., Ltd. | — | — | — | 0 |
| MPB | Mid Penn Bancorp, Inc. | Financial Services | $917M | — | 0 |
| MAA-PI | Mid-America Apartment Communities, Inc. | Real Estate | $14.8B | — | 0 |
| MFICL | MidCap Financial Investment Corporation 8.00% Notes due 2028 | Financial Services | $2.3B | — | 0 |
| MSEXP | Middlesex Water Company PFD 7% | Utilities | $822M | — | 0 |
| MGCOF | Midea Group Co., Ltd./ADR | — | — | — | 0 |
| MFP | Midera Food Processing, Inc. | Industrials | $1.9B | — | 0 |
| MSBIP | Midland States Bancorp, Inc. | Financial Services | $701M | — | 0 |
| MIST | Milestone Pharmaceuticals Inc. | Healthcare | $99.0M | — | 0 |
| MLSS | Milestone Scientific Inc. | Healthcare | $35.4M | — | 0 |
| MILIF | Military Metals Corp. | — | — | — | 0 |
| MGIH | Millennium Group International Holdings Limited | Consumer Cyclical | $16.9M | — | 0 |
| MLR | Miller Industries, Inc. | Consumer Cyclical | $614M | — | 0 |
| MLKN | MillerKnoll, Inc. | Consumer Cyclical | $1.4B | — | 0 |
| MLCMF | Millicom International Cellular S.A. | — | — | — | 0 |
| MRP | Millrose Properties, Inc. | Real Estate | $4.2B | — | 0 |
| MMTRS | Mills Music Trust | Industrials | $6.4M | — | 0 |
| MMTXW | Miluna Acquisition Corp Warrant | Financial Services | $0.9M | — | 0 |