Westfield Capital Management’s Insmed INSM Stock Holding History

Westfield Capital Management’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	$174M	Buy	1,629,561 +161,102	+11%	+$19.5M	0.57%	47
2026 Q1	$240M	Buy	1,468,459 +1,035,938	+240%	+$159M	1.01%	18
2025 Q4	$75.3M	Sell	432,521 -55,406	-11%	-$10.1M	0.31%	105
2025 Q3	$70.3M	Sell	487,927 -851,361	-64%	-$104M	0.29%	100
2025 Q2	$135M	Sell	1,339,288 -67,321	-5%	-$5.15M	0.57%	41
2025 Q1	$107M	Buy	1,406,609 +468,058	+50%	+$35.8M	0.52%	54
2024 Q4	$64.8M	Buy	938,551 +686,812	+273%	+$49.5M	0.28%	108
2024 Q3	$18.4M	Buy	+251,739	New	+$18.6M	0.08%	184
2021 Q3	–	Sell	-967,079	Closed	-$27.5M	–	249
2021 Q2	$27.5M	Sell	967,079 -56,133	-5%	-$1.67M	0.16%	163
2021 Q1	$34.9M	Sell	1,023,212 -255,464	-20%	-$9.76M	0.22%	139
2020 Q4	$42.6M	Sell	1,278,676 -53,812	-4%	-$1.97M	0.25%	133
2020 Q3	$42.8M	Buy	1,332,488 +295,777	+29%	+$8.5M	0.28%	115
2020 Q2	$28.6M	Buy	+1,036,711	New	+$24.6M	0.2%	137

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

Westfield Capital Management's INSM Position: Q2 2026 in Review

Westfield Capital Management increased its Insmed (INSM) stake by 11% in Q2 2026, buying an estimated $19.5M and bringing the position to 1,629,561 shares worth $174M. The position accounts for 0.57% of the portfolio, ranked #47.

Westfield Capital Management first reported a position in INSM in Q2 2020 and has held it in 13 quarters since. The position peaked at $240M in Q1 2026. 665 funds tracked by Wall St. Rank hold INSM as of Q2 2026.

Westfield Capital Management held 1,629,561 shares of Insmed worth $174M as of Q2 2026.
Westfield Capital Management bought 161,102 Insmed shares in Q2 2026, an estimated $19.5M.
Insmed made up 0.57% of Westfield Capital Management's portfolio in Q2 2026, its #47 holding.
Westfield Capital Management first reported a position in Insmed in Q2 2020 and has held it in 13 quarters since.
Westfield Capital Management's Insmed position peaked at $240M in Q1 2026.
665 funds tracked by Wall St. Rank held Insmed as of Q2 2026.

Based on Westfield Capital Management's 13F filing for Q2 2026, filed 12 Aug 2026.