Castle Hook Partners’s Insmed INSM Stock Holding History

Castle Hook Partners’s Portfolio INSM Stock Details INSM Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q2	$106M	Sell	993,310 -276,444	-22%	-$33.5M	0.49%	31
2026 Q1	$208M	Buy	1,269,754 +16,186	+1%	+$2.49M	0.89%	14
2025 Q4	$218M	Buy	1,253,568 +162,163	+15%	+$29.6M	0.91%	20
2025 Q3	$157M	Buy	1,091,405 +638,749	+141%	+$78.3M	0.8%	22
2025 Q2	$45.6M	Buy	+452,656	New	+$34.6M	0.26%	44
2021 Q2	–	Sell	-217,870	Closed	-$7.42M	–	76
2021 Q1	$7.42M	Buy	+217,870	New	+$8.33M	0.68%	30

Other funds holding INSM

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

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

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

JP Morgan Chase New York $1.81T AUM 41.13% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

BBA

Baker Bros. Advisors New York $20B AUM 154.41% 1-Year Est. Return

Capital International Investors Los Angeles, California $484B AUM 34.9% 1-Year Est. Return

DGM

Darwin Global Management St. Helier, Jersey $3.76B AUM 342.13% 1-Year Est. Return

Ameriprise Minneapolis, Minnesota $495B AUM 43.24% 1-Year Est. Return

OAG

Orbis Allan Gray Hamilton, Bermuda $29.1B AUM 60.8% 1-Year Est. Return

Castle Hook Partners's INSM Position: Q2 2026 in Review

Castle Hook Partners reduced its Insmed (INSM) stake by 22% in Q2 2026, selling an estimated $33.5M and leaving 993,310 shares worth $106M. The position accounts for 0.49% of the portfolio, ranked #31.

Castle Hook Partners first reported a position in INSM in Q1 2021 and has held it in 6 quarters since. The position peaked at $218M in Q4 2025. 665 funds tracked by Wall St. Rank hold INSM as of Q2 2026.

Castle Hook Partners held 993,310 shares of Insmed worth $106M as of Q2 2026.
Castle Hook Partners sold 276,444 Insmed shares in Q2 2026, an estimated $33.5M.
Insmed made up 0.49% of Castle Hook Partners's portfolio in Q2 2026, its #31 holding.
Castle Hook Partners first reported a position in Insmed in Q1 2021 and has held it in 6 quarters since.
Castle Hook Partners's Insmed position peaked at $218M in Q4 2025.
665 funds tracked by Wall St. Rank held Insmed as of Q2 2026.

Based on Castle Hook Partners's 13F filing for Q2 2026, filed 14 Aug 2026.