Based on data from the past 90 days ending February 19, 2026, Maxcyte's three largest insider shareholders are TenPercentOwner Partners Master Fund, L.P. Casdin (10.00Mn shares), Director Stanley C Erck (398.33K shares), Director Art Mandell (395.85K shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Partners Master Fund, L.P. Casdin | 10,000,000 | 05 Oct, 2022 | |
| Stanley C Erck | 398,328 | 13 Aug, 2025 | |
| Art Mandell | 395,851 | 13 Jun, 2024 | |
| Douglas Doerfler | President And Ceo | 333,197 | 06 Dec, 2023 |
| Richard Douglas | 230,577 | 13 Aug, 2025 | |
| Maher Masoud | President And Ceo | 175,000 | 13 Aug, 2025 |
| John Joseph Johnston | 171,160 | 23 Jun, 2025 | |
| Douglas J Swirsky | Chief Financial Officer | 161,811 | 13 Aug, 2025 |
| William W Brooke | 150,879 | 13 Aug, 2025 | |
| Ron Holtz | Svp And Cao | 125,251 | 16 Nov, 2021 |
| Cynthia Collins | 80,889 | 23 Jun, 2025 | |
| David I. Sandoval | General Counsel | 64,219 | 20 Mar, 2025 |
| Ali Soleymannezhad | Chief Commercial Officer | 59,439 | 20 Mar, 2025 |
| Yasir B. Al-Wakeel | 50,577 | 23 Jun, 2025 | |
| Patrick J Balthrop | 50,577 | 23 Jun, 2025 | |
| Rekha Hemrajani | 39,893 | 27 Aug, 2025 | |
| Thomas M. Ross | Evp And Global Sales | 25,000 | 05 Aug, 2024 |
* 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 |
|---|---|---|---|---|---|---|---|---|
| 13 Aug, 2025 | Richard Douglas | Common Stock | A | 80,000 | $1.39 | 230,577 | D | P |
| 13 Aug, 2025 | Stanley C Erck | Common Stock | A | 100,000 | $1.37 | 398,328 | D | P |
| 13 Aug, 2025 | Douglas J Swirsky | Common Stock | A | 50,000 | $1.29 | 161,811 | D | P |
| 13 Aug, 2025 | William W Brooke | Common Stock | A | 50,000 | $1.29 | 150,879 | D | P |
| 13 Aug, 2025 | Maher Masoud | Common Stock | A | 75,000 | $1.37 | 175,000 | D | P |
| 25 Jun, 2025 | Rekha Hemrajani | Common Stock | D | 10,684 | $2.09 | 39,893 | D | S |
| 18 Jun, 2025 | Richard Douglas | Common Stock | A | 29,210 | $0.00 | 150,577 | D | A |
| 18 Jun, 2025 | Patrick J Balthrop | Common Stock | A | 29,210 | $0.00 | 50,577 | D | A |
| 18 Jun, 2025 | Patrick J Balthrop | - | - | 50,577 | D | |||
| 18 Jun, 2025 | Stanley C Erck | Common Stock | A | 29,210 | $0.00 | 298,328 | D | A |
| 18 Jun, 2025 | Cynthia Collins | Common Stock | A | 29,210 | $0.00 | 80,889 | D | A |
| 18 Jun, 2025 | William W Brooke | Common Stock | A | 29,210 | $0.00 | 100,879 | D | A |
| 18 Jun, 2025 | Yasir B. Al-Wakeel | Common Stock | A | 29,210 | $0.00 | 50,577 | D | A |
| 18 Jun, 2025 | Rekha Hemrajani | Common Stock | A | 29,210 | $0.00 | 50,577 | D | A |
| 18 Jun, 2025 | John Joseph Johnston | Common Stock | A | 29,210 | $0.00 | 171,160 | D | A |
| 18 Mar, 2025 | Douglas J Swirsky | Common Stock | D | 6,939 | $3.18 | 111,811 | D | S |
| 18 Mar, 2025 | David I. Sandoval | Common Stock | D | 353 | $3.18 | 64,219 | D | S |
| 18 Mar, 2025 | Ali Soleymannezhad | Common Stock | D | 1,211 | $3.18 | 59,439 | D | S |
| 14 Mar, 2025 | Douglas J Swirsky | Common Stock | A | 37,500 | $0.00 | 118,750 | D | A |
| 14 Mar, 2025 | David I. Sandoval | Common Stock | A | 23,125 | $0.00 | 64,572 | D | A |