EcoR1 Capital’s Dyne Therapeutics DYN Stock Holding History

EcoR1 Capital’s Portfolio DYN Stock Details DYN Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2025 Q1	–	Sell	-555,644	Closed	-$13.1M	–	51
2024 Q4	$13.1M	Hold	555,644	–	–	0.49%	35
2024 Q3	$20M	Buy	555,644 +128,605	+30%	+$5.12M	0.68%	34
2024 Q2	$15.1M	Hold	427,039	–	–	0.46%	39
2024 Q1	$12.1M	Buy	+427,039	New	+$9.66M	0.31%	42
2023 Q3	–	Sell	-798,701	Closed	-$8.99M	–	53
2023 Q2	$8.99M	Sell	798,701 -1,523,683	-66%	-$18M	0.22%	35
2023 Q1	$26.8M	Hold	2,322,384	–	–	0.86%	17
2022 Q4	$26.9M	Buy	+2,322,384	New	+$26.9M	0.82%	24
2022 Q3	–	Sell	-215,000	Closed	-$1.48M	–	80
2022 Q2	$1.48M	Hold	215,000	–	–	0.05%	63
2022 Q1	$2.07M	Hold	215,000	–	–	0.06%	64
2021 Q4	$2.56M	Hold	215,000	–	–	0.08%	55
2021 Q3	$3.57M	Hold	215,000	–	–	0.12%	48
2021 Q2	$4.52M	Hold	215,000	–	–	0.17%	44
2021 Q1	$3.34M	Hold	215,000	–	–	0.15%	47
2020 Q4	$4.51M	Hold	215,000	–	–	0.24%	43
2020 Q3	$4.34M	Buy	+215,000	New	+$4.72M	0.31%	33

Other funds holding DYN

Janus Henderson Group London $209B AUM 37.72% 1-Year Est. Return

RCM

RA Capital Management Boston, Massachusetts $11.5B AUM 168.77% 1-Year Est. Return

AVLSA

Atlas Venture Life Science Advisors Cambridge, Massachusetts $881M AUM 160.77% 1-Year Est. Return

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return

FIS

FCPM III Services Naarden, Netherlands $750M AUM 127.27% 1-Year Est. Return

Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return

Braidwell Stamford, Connecticut $2.7B AUM 88.53% 1-Year Est. Return

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Citadel Advisors Miami, Florida $875B AUM 40.91% 1-Year Est. Return

EcoR1 Capital's DYN Position: Q1 2025 in Review

EcoR1 Capital sold out of Dyne Therapeutics (DYN) in Q1 2025, closing a stake of 555,644 shares — an estimated $13.1M sold.

EcoR1 Capital first reported a position in DYN in Q3 2020 and held it in 15 quarters. The position peaked at $26.9M in Q4 2022. 205 funds tracked by Wall St. Rank hold DYN as of Q1 2025.

EcoR1 Capital reported no remaining Dyne Therapeutics position as of Q1 2025 after selling out during the quarter.
EcoR1 Capital sold 555,644 Dyne Therapeutics shares in Q1 2025, an estimated $13.1M.
EcoR1 Capital first reported a position in Dyne Therapeutics in Q3 2020 and held it in 15 quarters.
EcoR1 Capital's Dyne Therapeutics position peaked at $26.9M in Q4 2022.
205 funds tracked by Wall St. Rank held Dyne Therapeutics as of Q1 2025.

Based on EcoR1 Capital's 13F filing for Q1 2025, filed 15 May 2025.