As of April 22, 2026, the three largest insider holders of MASS are Christopher D. Brown (Chief Product Officer, 945.56K shares), Christopher D. Brown (Chief Technology Officer, 892.38K shares), Kevin J. Knopp (President And Ceo, 795.97K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Christopher D. Brown | Chief Product Officer | 945,559 | 0 | 10 Apr, 2026 |
| Christopher D. Brown | Chief Technology Officer | 892,375 | 0 | 25 May, 2023 |
| Kevin J. Knopp | President And Ceo | 795,968 | 0 | 03 Feb, 2026 |
| Kevin J. Knopp | President And Ceo | 795,968 | 0 | 03 Feb, 2026 |
| Kevin J. Knopp | President And Ceo | 795,968 | 0 | 03 Feb, 2026 |
| Kevin J. Knopp | President And Ceo | 367,848 | 0 | 25 May, 2023 |
| Kevin J. Knopp | President And Ceo | 367,848 | 0 | 25 May, 2023 |
| Kevin J. Knopp | President And Ceo | 367,848 | 0 | 25 May, 2023 |
| E Kevin Hrusovsky | - | 320,571 | 0 | 22 Nov, 2022 |
| E Kevin Hrusovsky | - | 320,571 | 0 | 22 Nov, 2022 |
| E Kevin Hrusovsky | - | 151,307 | 0 | 13 Jun, 2025 |
| E Kevin Hrusovsky | - | 151,307 | 0 | 13 Jun, 2025 |
| Joseph H. Iv Griffith | Chief Financial Officer | 139,896 | 0 | 03 Feb, 2026 |
| Joseph H. Iv Griffith | Chief Financial Officer | 139,896 | 0 | 03 Feb, 2026 |
| Joseph H. Iv Griffith | Chief Financial Officer | 139,896 | 0 | 03 Feb, 2026 |
| Joseph H. Iv Griffith | Chief Financial Officer | 93,437 | 0 | 27 Mar, 2024 |
| Joseph H. Iv Griffith | Chief Financial Officer | 93,437 | 0 | 27 Mar, 2024 |
| Joseph H. Iv Griffith | Chief Financial Officer | 93,437 | 0 | 27 Mar, 2024 |
| Trent A. Basarsky | Vp, Corporate Development | 80,000 | 0 | 28 Apr, 2022 |
| Trent A. Basarsky | Vp, Corporate Development | 80,000 | 0 | 28 Apr, 2022 |
| Trent A. Basarsky | Vp, Corporate Development | 80,000 | 0 | 28 Apr, 2022 |
| Mark Spoto | - | 74,335 | 0 | 13 Jun, 2025 |
| Mark Spoto | - | 74,335 | 0 | 13 Jun, 2025 |
| Mark Spoto | - | 74,335 | 0 | 13 Jun, 2025 |
| Kevin J. Mccallion | Svp, Products And Production | 44,925 | 0 | 14 Apr, 2026 |
| Mark Spoto | - | 40,423 | 0 | 23 Nov, 2022 |
| Mark Spoto | - | 40,423 | 0 | 23 Nov, 2022 |
| Mark Spoto | - | 40,423 | 0 | 23 Nov, 2022 |
| Trent A. Basarsky | Vp, Corporate Development | 35,000 | 0 | 27 Sep, 2021 |
| Trent A. Basarsky | Vp, Corporate Development | 35,000 | 0 | 27 Sep, 2021 |
| Trent A. Basarsky | Vp, Corporate Development | 35,000 | 0 | 27 Sep, 2021 |
| Anthony Hunt | - | 30,085 | 0 | 13 Jun, 2025 |
| Anthony Hunt | - | 30,085 | 0 | 13 Jun, 2025 |
| Anthony Hunt | - | 30,085 | 0 | 13 Jun, 2025 |
| Fenel M Eloi | - | 26,814 | 0 | 13 Jun, 2025 |
| Jeffrey P. George | - | 26,814 | 0 | 13 Jun, 2025 |
| Jeffrey P. George | - | 26,814 | 0 | 13 Jun, 2025 |
| Fenel M Eloi | - | 26,814 | 0 | 13 Jun, 2025 |
| Jeffrey P. George | - | 26,814 | 0 | 13 Jun, 2025 |
| Marcia Eisenberg | - | 25,957 | 0 | 13 Jun, 2025 |
| Marcia Eisenberg | - | 25,957 | 0 | 13 Jun, 2025 |
| Marcia Eisenberg | - | 25,957 | 0 | 13 Jun, 2025 |
| Anthony Hunt | - | 8,886 | 0 | 05 Mar, 2024 |
| Anthony Hunt | - | 8,886 | 0 | 05 Mar, 2024 |
| Anthony Hunt | - | 8,886 | 0 | 05 Mar, 2024 |
| Jeffrey P. George | - | 7,673 | 0 | 22 Feb, 2024 |
| Fenel M Eloi | - | 7,673 | 0 | 23 Feb, 2024 |
| Jeffrey P. George | - | 7,673 | 0 | 22 Feb, 2024 |
| Jeffrey P. George | - | 7,673 | 0 | 22 Feb, 2024 |
| Fenel M Eloi | - | 7,673 | 0 | 23 Feb, 2024 |
| Michele M. Leonhart | - | 6,485 | 0 | 27 Jun, 2025 |
| Michele M. Leonhart | - | 6,485 | 0 | 27 Jun, 2025 |
| Michele M. Leonhart | - | 6,485 | 0 | 27 Jun, 2025 |
| Maura Fitzpatrick | Vp, Product Management Mktg | 2,834 | 0 | 03 Feb, 2023 |
| Maura Fitzpatrick | Vp, Product Management Mktg | 2,834 | 0 | 03 Feb, 2023 |
| Maura Fitzpatrick | Vp, Product Management Mktg | 2,834 | 0 | 03 Feb, 2023 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 10 Apr, 2026 | Kevin J. Mccallion | Common Stock | A | 2,693 | $1.05 | 47,618 | D | M |
| 10 Apr, 2026 | Kevin J. Mccallion | Common Stock | D | 2,693 | $7.01 | 44,925 | D | S |
| 10 Apr, 2026 | Kevin J. Mccallion | Stock Option (right to buy) | D | 2,693 | $0.00 | 0 | D | M |
| 08 Apr, 2026 | Christopher D. Brown | Common Stock | D | 15,030 | $7.05 | 970,529 | D | S |
| 08 Apr, 2026 | Kevin J. Mccallion | Common Stock | A | 18,580 | $1.05 | 63,505 | D | M |
| 09 Apr, 2026 | Christopher D. Brown | Common Stock | D | 7,392 | $7.04 | 963,137 | D | S |
| 08 Apr, 2026 | Kevin J. Mccallion | Common Stock | D | 18,580 | $7.05 | 44,925 | D | S |
| 10 Apr, 2026 | Christopher D. Brown | Common Stock | D | 17,578 | $7.07 | 945,559 | D | S |
| 09 Apr, 2026 | Kevin J. Mccallion | Common Stock | A | 5,420 | $1.05 | 50,345 | D | M |
| 09 Apr, 2026 | Kevin J. Mccallion | Common Stock | D | 5,420 | $7.03 | 44,925 | D | S |
| 08 Apr, 2026 | Kevin J. Mccallion | Stock Option (right to buy) | D | 18,580 | $0.00 | 8,106 | D | M |
| 09 Apr, 2026 | Kevin J. Mccallion | Stock Option (right to buy) | D | 5,420 | $0.00 | 2,686 | D | M |
| 02 Mar, 2026 | Kevin J. Mccallion | Common Stock | D | 7 | $7.00 | 44,918 | D | S |
| 02 Mar, 2026 | Kevin J. Mccallion | Common Stock | A | 7 | $1.05 | 44,932 | D | M |
| 02 Mar, 2026 | Kevin J. Mccallion | Common Stock | D | 7 | $7.00 | 44,925 | D | S |
| 02 Mar, 2026 | Kevin J. Mccallion | Stock Option (right to buy) | D | 7 | $0.00 | 26,686 | D | M |
| 01 Feb, 2026 | Kevin J. Knopp | Common Stock | A | 11,255 | - | 733,988 | D | M |
| 01 Feb, 2026 | Joseph H. Iv Griffith | Common Stock | A | 5,102 | - | 98,032 | D | M |
| 01 Feb, 2026 | Christopher D. Brown | Common Stock | A | 5,027 | - | 967,149 | D | M |
| 01 Feb, 2026 | Christopher D. Brown | Common Stock | A | 7,418 | - | 974,567 | D | M |