EcoR1 Capital’s Avidity Biosciences RNAM Stock Holding History

EcoR1 Capital’s Portfolio RNAM Stock Details RNAM Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2025 Q4	–	Sell	-765,000	Closed	-$33.3M	–	39
2025 Q3	$33.3M	Buy	765,000 +265,000	+53%	+$10.7M	1.6%	16
2025 Q2	$14.2M	Sell	500,000 -57,576	-10%	-$1.72M	0.84%	23
2025 Q1	$16.5M	Hold	557,576	–	–	0.98%	19
2024 Q4	$16.2M	Sell	557,576 -200,000	-26%	-$8.36M	0.61%	30
2024 Q3	$34.8M	Hold	757,576	–	–	1.19%	22
2024 Q2	$30.9M	Hold	757,576	–	–	0.95%	24
2024 Q1	$19.3M	Buy	+757,576	New	+$11.9M	0.49%	37
2022 Q4	–	Sell	-2,899,285	Closed	-$47.3M	–	72
2022 Q3	$47.3M	Buy	2,899,285 +139,780	+5%	+$2.67M	1.4%	17
2022 Q2	$40.1M	Hold	2,759,505	–	–	1.38%	23
2022 Q1	$51M	Hold	2,759,505	–	–	1.59%	19
2021 Q4	$65.6M	Hold	2,759,505	–	–	2.09%	14
2021 Q3	$68M	Buy	2,759,505 +655,555	+31%	+$14.2M	2.36%	13
2021 Q2	$52M	Hold	2,103,950	–	–	1.94%	15
2021 Q1	$45.9M	Hold	2,103,950	–	–	2.04%	15
2020 Q4	$53.7M	Hold	2,103,950	–	–	2.89%	14
2020 Q3	$59.2M	Hold	2,103,950	–	–	4.22%	8
2020 Q2	$59.5M	Buy	+2,103,950	New	+$60.7M	4.39%	9

Other funds holding RNAM

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

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

RCM

RA Capital Management Boston, Massachusetts $9.44B AUM 157.3% 1-Year Est. Return

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

Balyasny Asset Management Chicago, Illinois $77.1B AUM 42.89% 1-Year Est. Return

PCM

Pentwater Capital Management Naples, Florida $19.3B AUM 58.13% 1-Year Est. Return

ACA

Avoro Capital Advisors New York $10.2B AUM 149.19% 1-Year Est. Return

HBK Investments Dallas, Texas $9.85B AUM 55.6% 1-Year Est. Return

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

Goldman Sachs New York $871B AUM 31.28% 1-Year Est. Return

EcoR1 Capital's RNAM Position: Q4 2025 in Review

EcoR1 Capital sold out of Avidity Biosciences (RNAM) in Q4 2025, closing a stake of 765,000 shares — an estimated $33.3M sold.

EcoR1 Capital first reported a position in RNAM in Q2 2020 and held it in 17 quarters. The position peaked at $68M in Q3 2021. 343 funds tracked by Wall St. Rank hold RNAM as of Q4 2025.

EcoR1 Capital reported no remaining Avidity Biosciences position as of Q4 2025 after selling out during the quarter.
EcoR1 Capital sold 765,000 Avidity Biosciences shares in Q4 2025, an estimated $33.3M.
EcoR1 Capital first reported a position in Avidity Biosciences in Q2 2020 and held it in 17 quarters.
EcoR1 Capital's Avidity Biosciences position peaked at $68M in Q3 2021.
343 funds tracked by Wall St. Rank held Avidity Biosciences as of Q4 2025.

Based on EcoR1 Capital's 13F filing for Q4 2025, filed 17 Feb 2026.