L3VLUP
Quarter end
30 Jun 2026
the date the book describes
Filed
27 Oct 2026
latest of these filings; the earliest 3 Aug 2026
Managers listing it
35
at least, of 95 tracked, among listed positions
Comparable managers
91
filed both Q1 2026 and Q2 2026; 18 listed it in both
Shares listed
49,111,808
combined, among listed positions
Reported value
$5.3bn
combined, at the quarter end

AllianceBernstein LP. Values in this filing are at the previous quarter end's prices; its share count is the quarter end's.

Among the 91 comparable managers: 28 buyers (opened or added shares) and 11 sellers (trimmed or exited), at least, among listed positions. Their net change in shares was +5,138,137.

Managers listing INSM in Q2 2026

Share of 13F value is the position’s reported value over everything the manager reported that quarter. The share change is against Q1 2026, and only where both filings list the position. A rise in value with no rise in shares is the price, not buying.

35 of 35 holders

ActionFiling
Fidelity (FMR LLC)16,143,583$1.7bn0.07%Added+2,983,41613 Aug 2026 (the filing on sec.gov)
D. E. Shaw & Co.5,877,959$627m0.30%Added+252,13414 Aug 2026 (the filing on sec.gov)
Artisan Partners LP5,441,718$580m0.92%Trimmed-1,085,58313 Aug 2026 (the filing on sec.gov)
T. Rowe Price Associates Inc3,405,290$363munder 0.1%Added+312,48314 Aug 2026 (the filing on sec.gov)
Janus Henderson Group Ltd2,605,181$278m0.11%Added+2,185,87714 Aug 2026 (the filing on sec.gov)
Citadel Advisors LLC2,556,973$273munder 0.1%Added+374,4022 Sep 2026 (the filing on sec.gov)
Maverick Capital Ltd2,150,762$229m2.03%Newnew14 Aug 2026 (the filing on sec.gov)
Millennium Management LLC2,048,005$218m0.08%Added+890,21914 Aug 2026 (the filing on sec.gov)
Balyasny Asset Management LLC1,326,430$141m0.18%Added+1,104,72314 Aug 2026 (the filing on sec.gov)
Two Sigma Investments LP1,242,222$132m0.10%Added+1,005,20514 Aug 2026 (the filing on sec.gov)
Susquehanna International Group LLP729,354$78munder 0.1%Added+555,72414 Aug 2026 (the filing on sec.gov)
AllianceBernstein LP462,796$76munder 0.1%Trimmed-225,93814 Aug 2026 (the filing on sec.gov)
Squarepoint Ops LLC616,464$66m0.07%Added+577,14814 Aug 2026 (the filing on sec.gov)
AQR Capital Management LLC612,832$65munder 0.1%Trimmed-62,65314 Aug 2026 (the filing on sec.gov)
Wellington Management Group LLP543,893$58munder 0.1%Added+144,84914 Aug 2026 (the filing on sec.gov)
Point72 Asset Management LP536,997$57m0.06%Newnew14 Aug 2026 (the filing on sec.gov)
Marshall Wace LLP501,930$54munder 0.1%Added+189,36513 Aug 2026 (the filing on sec.gov)
Bridgewater Associates LP455,392$49m0.20%Added+159,81314 Aug 2026 (the filing on sec.gov)
Neuberger Berman Group LLC378,816$40munder 0.1%Added+108,11627 Oct 2026 (the filing on sec.gov)
Invesco Ltd368,261$39munder 0.1%Trimmed-6,144,62814 Aug 2026 (the filing on sec.gov)
Tudor Investment Corp195,391$21munder 0.1%Newnew14 Aug 2026 (the filing on sec.gov)
Jane Street Group LLC193,528$21munder 0.1%Added+182,12714 Aug 2026 (the filing on sec.gov)
Holocene Advisors LP192,879$21munder 0.1%Newnew14 Aug 2026 (the filing on sec.gov)
Woodline Partners LP152,618$16m0.05%Added+4,16514 Aug 2026 (the filing on sec.gov)
Hudson Bay Capital Management LP109,352$12munder 0.1%Newnew14 Aug 2026 (the filing on sec.gov)
Page 1 of 2

Largest increases and reductions, by shares

Q1 2026 to Q2 2026, among managers that listed it in both quarters or opened it.

Increases

Reductions

New positions and exits

At least these many: a manager is shown exiting only where its own filing shows the position gone.

Ownership over time

Every quarter on file. A quarter-end value moves with the price as well as with the shares held; buyers and sellers count comparable managers, by shares.
18 in Q3 2024 to 21 in Q2 2026

Tracked managers listing it, at least.

0102030201420182020202220242026
the quarter shown share split complete books; unmarked quarters rest on listed positionsClick a quarter to open it.
INSM by quarter
QuarterHoldersReported valueBuyersSellers
Q3 20131$20mn.a.n.a.
Q4 20131$28mn.a.n.a.
Q1 20142$39mn.a.n.a.
Q2 20142$43mn.a.n.a.
Q3 20141$34mn.a.n.a.
Q4 20141$44mn.a.n.a.
Q1 20151$174mn.a.n.a.
Q2 20151$211mn.a.n.a.
Q3 20151$168mn.a.n.a.
Q4 20152$169mn.a.n.a.
Q3 20161$146mn.a.n.a.
Q1 20171$189mn.a.n.a.
Q2 20174$180mn.a.n.a.
Q3 20177$890mn.a.n.a.
Q4 20174$954mn.a.n.a.
Q1 20183$428mn.a.n.a.
Q2 20183$475mn.a.n.a.
Q3 20184$416mn.a.n.a.
Q4 20181$150mn.a.n.a.
Q1 20194$897mn.a.n.a.
Q2 20196$559mn.a.n.a.
Q3 20196$284mn.a.n.a.
Q4 20196$680mn.a.n.a.
Q1 20207$472mn.a.n.a.
Q2 20207$1.0bnn.a.n.a.
Q3 20209$1.2bnn.a.n.a.
Q4 20208$1.0bnn.a.n.a.
Q1 20216$816mn.a.n.a.
Q2 20216$800mn.a.n.a.
Q3 20217$803mn.a.n.a.
Q4 20217$760mn.a.n.a.
Q1 20228$680mn.a.n.a.
Q2 20227$566mn.a.n.a.
Q3 202210$379mn.a.n.a.
Q4 20228$360mn.a.n.a.
Q1 20236$282mn.a.n.a.
Q2 20236$353mn.a.n.a.
Q3 20237$415mn.a.n.a.
Q4 20238$539m45
Q1 20248$437m73
Q2 202416$2.2bn106
Q3 202418$2.3bn1010
Q4 202414$1.6bn48
Q1 202514$1.9bn94
Q2 202523$3.7bn176
Q3 202520$5.8bn109
Q4 202519$6.6bn1420
Q1 202619$7.0bn1617
Q2 202621$5.0bn2811

Compare with…

Holders over time, buyers and sellers, and the managers holding both, side by side for up to four stocks.

INSM and LLY →INSM and JNJ →INSM and VRTX →Choose a stock to compare with INSM →

How much of the picture this is

A 13F is a manager’s long US-listed equity book at a quarter end, filed up to 45 days later. It shows no shorts, cash, bonds or performance, and it is never today’s portfolio. Large books are listed to their largest positions, so a manager missing from this table may still hold a small position below that line. These are 95 tracked managers, not the institutional market.

Which funds own INSM, latest filings →Back to the 13F Explorer →