Maxcyte, Inc. (MXCT) Insider Ownership

Historic Insider Ownership Trends

As of April 22, 2026, the three largest insider holders of MXCT are Partners Master Fund, L.P. Casdin (TenPercentOwner, 10.00Mn shares), Partners Master Fund, L.P. Casdin (TenPercentOwner, 10.00Mn shares), Partners Master Fund, L.P. Casdin (TenPercentOwner, 10.00Mn shares).

Top Direct Holders

Insider ownership data is derived from the last 60 months of Form 4 SEC filings.
Holder Position Shares (Direct) Shares (Indirect) Report Date
Partners Master Fund, L.P. Casdin - 10,000,000 0 05 Oct, 2022
Partners Master Fund, L.P. Casdin - 10,000,000 0 05 Oct, 2022
Partners Master Fund, L.P. Casdin - 10,000,000 0 05 Oct, 2022
Maher Masoud President And Ceo 475,000 0 31 Mar, 2026
Maher Masoud President And Ceo 475,000 0 31 Mar, 2026
Stanley C Erck - 398,328 0 13 Aug, 2025
Art Mandell - 395,851 0 13 Jun, 2024
Art Mandell - 395,851 0 13 Jun, 2024
Douglas Doerfler President And Ceo 333,197 0 06 Dec, 2023
Richard Douglas - 230,577 0 13 Aug, 2025
John Joseph Johnston - 171,160 0 23 Jun, 2025
Douglas J Swirsky Chief Financial Officer 151,669 0 19 Mar, 2026
Douglas J Swirsky Chief Financial Officer 151,669 0 19 Mar, 2026
William W Brooke - 150,879 0 13 Aug, 2025
Ron Holtz Svp And Cao 125,251 0 16 Nov, 2021
Cynthia Collins - 80,889 0 23 Jun, 2025
David I. Sandoval General Counsel 64,219 0 20 Mar, 2025
David I. Sandoval General Counsel 64,219 0 20 Mar, 2025
Ali Soleymannezhad Chief Commercial Officer 59,439 0 20 Mar, 2025
Ali Soleymannezhad Chief Commercial Officer 59,439 0 20 Mar, 2025
Yasir B. Al-Wakeel - 50,577 0 23 Jun, 2025
Patrick J Balthrop - 50,577 0 23 Jun, 2025
Rekha Hemrajani - 39,893 0 27 Aug, 2025
Thomas M. Ross Evp, Global Sales 25,000 0 05 Aug, 2024
Thomas M. Ross Evp, Global Sales 25,000 0 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.

Recent Insider Transactions

Detailed insider trading activity based on Form 4 SEC filings.
Download Data
Transaction Date Insider Name Security Class Transaction Type Shares Traded Price Shares Remaining Ownership Code
30 Mar, 2026 Parmeet Ahuja Employee Stock Option (right to buy) A 375,000 $0.00 375,000 D A
27 Mar, 2026 Maher Masoud Common Stock A 300,000 $0.00 475,000 D A
27 Mar, 2026 Maher Masoud Employee Stock Option (right to buy) A 600,000 $0.00 600,000 D A
17 Mar, 2026 Douglas J Swirsky Common Stock D 10,142 $0.82 151,669 D S
25 Jun, 2025 Rekha Hemrajani Common Stock D 10,684 $2.09 39,893 D S
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
13 Aug, 2025 Stanley C Erck Common Stock A 100,000 $1.37 398,328 D P
13 Aug, 2025 Richard Douglas Common Stock A 80,000 $1.39 230,577 D P
18 Jun, 2025 Stanley C Erck Common Stock A 29,210 $0.00 298,328 D A
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 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 Cynthia Collins Common Stock A 29,210 $0.00 80,889 D A
18 Jun, 2025 John Joseph Johnston Common Stock A 29,210 $0.00 171,160 D A
18 Jun, 2025 William W Brooke Common Stock A 29,210 $0.00 100,879 D A
18 Jun, 2025 John Joseph Johnston Stock Option (right to buy) A 50,790 $0.00 50,790 D A
18 Jun, 2025 Cynthia Collins Stock Option (right to buy) A 50,790 $0.00 50,790 D A