Rock Springs Capital Management LP

Position in DYN — Dyne Therapeutics, Inc.

CIK 1595725 Baltimore, MD

Position in DYN

as of Mar 31, 2026 · filed May 15, 2026 Compact

Position Value

$17,625,949

-$231,450 QoQ

Shares Held

972,198

+6.5% QoQ

Ownership

0.681%

of shares outstanding

% of Portfolio

1.04%

of 13F equity value

Holder Rank

—

not a current holder

Holding Since

Mar 2024

9 quarters on record

Voting authority Sole 100.ToString("F0")% Shared 0.ToString("F0")% None 0.ToString("F0")%

Healthcare · as of Mar 31, 2026

Rock Springs Capital Management LP holds $1,246,050,197 across 66 Biotechnology names. DYN ranks #24 (1.4% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	RVMD	Revolution Medicines, Inc.	1,209,465	$117,620,471
2	MDGL	Madrigal Pharmaceuticals, Inc.	170,999	$89,512,846
3	MIRM	Mirum Pharmaceuticals, Inc.	811,294	$74,947,339
4	ARGX	Argenx SE	98,500	$71,929,625
5	RYTM	Rhythm Pharmaceuticals, Inc.	689,748	$59,987,383
6	INSM	INSMED Inc	314,300	$51,394,336
7	ASND	Ascendis Pharma A/S	194,000	$44,373,620
8	XENE	Xenon Pharmaceuticals Inc.	763,020	$44,369,613

9 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-03-31	$17,625,949	972,198	+6.5%	Shares	Sole	2026-05-15
2025-12-31	$17,857,399	912,955	+10.8%	Shares	Sole	2026-02-17
2025-09-30	$10,424,371	824,061	+41.8%	Shares	Sole	2025-11-14
2025-06-30	$5,531,100	580,998	+10.8%	Shares	Sole	2025-08-14
2025-03-31	$5,486,259	524,499	+10.5%	Shares	Sole	2025-05-15
2024-12-31	$11,179,879	474,528	+2.9%	Shares	Sole	2025-02-14
2024-09-30	$16,560,125	461,028	0.0%	Shares	Sole	2024-11-14
2024-06-30	$16,269,678	461,028	+2.0%	Shares	Sole	2024-08-14
2024-03-31	$12,827,283	451,824	—	Shares	Sole	2024-05-15
No filing history on record for this holder in this stock.