As of September 29, 2026, the three largest insider holders of MUX are Robert Ross Mcewen (Chairman And Ceo, 8.24Mn shares), Robert Ross Mcewen (Chairman And Ceo, 1.53Mn shares), William M Shaver (Chief Operating Officer, 171.09K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Robert Ross Mcewen | Chairman And Ceo | 1,526,785 | 8,236,647 | 9,763,432 | 97.2% | 29 Jul, 2026 |
| 2 | William M Shaver | Chief Operating Officer | 171,086 | 0 | 171,086 | 1.7% | 30 Jun, 2026 |
| 3 | Perry Ing | Chief Financial Officer | 48,094 | 0 | 48,094 | 0.5% | 30 Jun, 2026 |
| 4 | Carmen L Diges | General Counsel/Corp Sec | 27,044 | 0 | 27,044 | 0.3% | 12 Nov, 2025 |
| 5 | Richard W. Brissenden | Director | 18,022 | 0 | 18,022 | 0.2% | 01 Jul, 2026 |
| 6 | Jeffrey Chan | Vp Finance | 4,775 | 0 | 4,775 | 0.0% | 30 Jun, 2026 |
| 7 | Stephan Michael Spears | Vp Corporate Development | 4,604 | 0 | 4,604 | 0.0% | 19 Nov, 2025 |
| 8 | G. Peter Mah | Chief Operating Officer | 3,158 | 0 | 3,158 | 0.0% | 15 Mar, 2022 |
| 9 | Nicolas Darveau-Garneau | Director | 2,285 | 0 | 2,285 | 0.0% | 10 Dec, 2024 |
| 10 | Stephen Douglas Kaszas | Director | 1,621 | 0 | 1,621 | 0.0% | 09 Jun, 2026 |
| 11 | Ian J Ball | Senior Vice President | 320 | 0 | 320 | 0.0% | 30 Jun, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 27 Jul, 2026 | Robert Ross Mcewen | Chairman And Ceo | Acquired A | 1,526,785 | — | — | 1,526,785 | Direct |
| 29 Jun, 2026 | Richard W. Brissenden | Director | Acquired M | 8,333 | $7.10 | $59.16K | 21,297 | Direct |
| 29 Jun, 2026 | Richard W. Brissenden | Director | Disposed S | 3,275 | $18.13 | $59.37K | 18,022 | Direct |
| 29 Jun, 2026 | Richard W. Brissenden | Director | Disposed M | 8,333 | $0.00 | $0 | 0 | Direct |
| 28 Jun, 2026 | Perry Ing | Chief Financial Officer | Acquired M | 270 | — | — | 46,864 | Direct |
| 28 Jun, 2026 | Jeffrey Chan | Vp Finance | Acquired M | 588 | — | — | 4,527 | Direct |
| 28 Jun, 2026 | Stephan Michael Spears | Vp Corporate Development | Disposed M | 1,200 | $0.00 | $0 | 0 | Direct |
| 29 Jun, 2026 | Ian J Ball | Director | Acquired M | 160 | — | — | 320 | Direct |
| 28 Jun, 2026 | Carmen L Diges | General Counsel/Corp Sec | Disposed M | 1,300 | $0.00 | $0 | 0 | Direct |
| 28 Jun, 2026 | William M Shaver | Chief Operating Officer | Acquired M | 2,100 | — | — | 151,300 | Direct |
| 28 Jun, 2026 | Jeffrey Chan | Vp Finance | Acquired M | 248 | — | — | 4,775 | Direct |
| 28 Jun, 2026 | Carmen L Diges | General Counsel/Corp Sec | Disposed M | 533 | $0.00 | $0 | 0 | Direct |
| 29 Jun, 2026 | Ian J Ball | Director | Disposed M | 310 | $0.00 | $0 | 310 | Direct |
| 28 Jun, 2026 | William M Shaver | Chief Operating Officer | Acquired M | 866 | — | — | 152,166 | Direct |
| 28 Jun, 2026 | Perry Ing | Chief Financial Officer | Acquired M | 116 | — | — | 46,980 | Direct |
| 28 Jun, 2026 | Stephan Michael Spears | Vp Corporate Development | Disposed M | 500 | $0.00 | $0 | 0 | Direct |
| 28 Jun, 2026 | Jeffrey Chan | Vp Finance | Disposed M | 1,266 | $0.00 | $0 | 0 | Direct |
| 29 Jun, 2026 | Carmen L Diges | General Counsel/Corp Sec | Disposed M | 3,370 | $0.00 | $0 | 0 | Direct |
| 29 Jun, 2026 | William M Shaver | Chief Operating Officer | Acquired M | 11,740 | — | — | 163,906 | Direct |
| 29 Jun, 2026 | Perry Ing | Chief Financial Officer | Acquired M | 686 | — | — | 47,666 | Direct |