Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share (MRSN) Institutional Ownership

13F Institutional Holders and Ownership History from Q2 2017 to Q3 2025

Type / Class
Equity / Common Stock, par value $0.0001 per share
Symbol
MRSN on Nasdaq
Shares outstanding
4,992,318
Price per share
$7.76
All holders as of 30 Sep 2025
Q3 2025
Total 13F shares
55,398
Total reported value
$410,881
% of total 13F portfolios
0%
Share change
-77,141,852
Value change
-$31,452,222
Number of holders
5
Price from insider filings
$7.76
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Significant Owners of Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share (MRSN) based on Schedule 13D/G filings

Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
Nextech Crossover I GP S.a r.l. 10% $4,344,209 12,067,246 Nextech Crossover I GP S.a. r.l. 20 Dec 2024
VANGUARD GROUP INC 6.7% $3,015,996 8,377,767 The Vanguard Group 31 Mar 2025
BlackRock, Inc. 3% -53% $1,103,358 -$1,338,033 3,761,876 -55% BlackRock, Inc. 30 Jun 2025
Venrock Healthcare Capital Partners III, L.P. 2.9% -68% $1,286,757 -$2,406,047 3,574,325 -65% Venrock Healthcare Capital Partners III, L.P. 31 Mar 2025
Schonfeld Strategic Advisors LLC 5.5% +19% $2,122,973 -$41,906,118 273,579 -95% Schonfeld Strategic Advisors LLC 30 Sep 2025

As of 30 Sep 2025, 5 institutional investors reported holding 55,398 shares of Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share (MRSN). This represents 1.1% of the company’s total 4,992,318 outstanding shares.

Institutional Holders of Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share (MRSN) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2025 Q3 55,398 $410,881 -$31,452,222 $7.76 5
2025 Q2 77,200,692 $22,849,022 -$3,437,337 $0.30 80
2025 Q1 87,949,584 $30,264,885 -$35,777,339 $0.34 109
2024 Q4 104,303,178 $149,151,003 -$24,954,008 $1.43 129
2024 Q3 116,077,343 $219,445,627 +$3,272,056 $1.89 115
2024 Q2 114,206,357 $229,554,281 -$23,968,075 $2.01 120
2024 Q1 117,492,700 $526,342,513 +$23,958,185 $4.48 124
2023 Q4 113,095,763 $262,379,163 +$21,039,242 $2.32 104
2023 Q3 113,738,083 $144,445,790 -$76,640,644 $1.27 127
2023 Q2 112,399,497 $369,792,616 +$12,845,282 $3.29 145
2023 Q1 106,632,085 $437,242,303 +$17,660,953 $4.11 156
2022 Q4 101,429,361 $594,377,218 +$41,420,886 $5.86 150
2022 Q3 92,449,667 $624,973,128 +$39,050,654 $6.76 147
2022 Q2 88,302,299 $407,955,031 +$36,774,738 $4.62 121
2022 Q1 80,872,131 $322,721,381 +$33,055,220 $3.99 127
2021 Q4 70,190,994 $436,594,924 -$9,658,535 $6.22 120
2021 Q3 68,748,658 $648,298,103 -$40,839,729 $9.43 108
2021 Q2 69,773,540 $946,957,788 -$9,186,549 $13.58 129
2021 Q1 68,154,863 $1,102,711,080 -$36,197,720 $16.18 130
2020 Q4 68,137,745 $1,813,136,515 +$51,864,511 $26.61 147
2020 Q3 67,909,081 $1,264,489,156 +$48,626,981 $18.62 132
2020 Q2 64,727,492 $1,514,580,389 +$684,777,923 $23.40 129
2020 Q1 40,118,913 $233,891,407 +$26,078,897 $5.83 82
2019 Q4 35,452,686 $203,141,553 -$5,999,927 $5.73 69
2019 Q3 38,476,429 $60,791,070 -$6,777,200 $1.58 73
2019 Q2 39,955,892 $161,842,717 +$11,993,581 $4.05 77
2019 Q1 36,929,163 $194,245,065 +$104,832,192 $5.26 65
2018 Q4 17,160,115 $70,012,155 -$10,222,226 $4.08 48
2018 Q3 19,817,013 $198,167,730 +$76,403 $10.00 46
2018 Q2 19,130,948 $341,677,448 +$7,606,792 $17.86 52
2018 Q1 18,728,332 $295,349,347 +$23,699,944 $15.77 56
2017 Q4 15,455,281 $253,897,465 -$4,017,344 $16.43 45
2017 Q3 15,693,839 $271,344,000 +$10,576,212 $17.29 40
2017 Q2 16,970,149 $236,408,000 +$236,408,000 $13.97 29