NAMSW · NewAmsterdam Pharma Co N.V. · Holdings

$8.25 -1.00 (-10.81%) At close · Oct 26 Q3 2025 earnings call transcript

Market Cap

$2.45B

119.54M

Volume · Oct 26 241 Avg daily vol (3M) 2621

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Use institutional holdings through the 13F API or MCP → See every holder of NAMSW: 13F, 13D and 13G, insiders and funds →

Some SEC filings for this period have not finished importing. Holder totals and changes may be incomplete; these filings remain queued for recovery.

Quarter:

Holders: 10

Total Value: $29,580,222

Total Shares: 1,384,194

Institutional Ownership Trend

16 quarters

Superinvestors Holding NAMSW

All superinvestors →

Andreas Halvorsen $142,458,885 Stanley Druckenmiller $104,047,247

Holder Concentration

Across 10 13F filers · Δ vs Mar 31, 2026

Top Holder

36.1%

−0.3 pts

Top 5

91.9%

−0.9 pts

Top 10

100.0%

0.0 pts

HHI

2,329

Moderately concentrated−43

Who Holds NAMSW

Last 8 quarters through Jun 30, 2026

Each kind of 13F filer's share of the common shares 13F filers report. Holder type comes from regulatory records, never the filer's name; style, turnover and horizon are measured from each filer's own 13F book. The quarter selector does not change this card.

Jun 30, 2026: 9 filers, like-for-like change +1.0%; actively managed books +1.0%.

Holder type	Share	Filers	Change
Registered adviser	91.8%	6	+1.1%
Bank	0.0%	1	+11.9%
Holding company	0.0%	0	—
Unknown	8.1%	2	0.0%

Style	Share	Filers	Change
Systematic-like	0.0%	0	—
Concentrated	78.4%	4	0.0%
Diversified active	21.6%	5	+4.8%
Not measured	0.0%	0	—
Unknown	0.0%	0	—

Turnover	Share	Filers	Change
Low turnover	63.7%	2	0.0%
Medium turnover	35.2%	6	0.0%
High turnover	1.1%	1	+601.7%
Not measured	0.0%	0	—
Unknown	0.0%	0	—

Holding horizon	Share	Filers	Change
Medium horizon	19.9%	2	0.0%
Long horizon	71.3%	5	0.0%
Short horizon	0.0%	0	—
Unknown	8.8%	2	+12.5%
Not measured	0.0%	0	—

13F book size	Share	Filers	Change
$1B to $10B	74.5%	7	+1.3%
$10B to $100B	25.5%	1	0.0%
$100B or more	0.0%	1	+11.9%
Under $1B	0.0%	0	—
Not measured	0.0%	0	—

Client base	Share	Filers	Change
Pooled investment vehicles	91.8%	6	+1.1%
Individuals and high net worth	0.0%	0	—
Diversified	0.0%	0	—
Unknown	8.2%	3	0.0%

Private funds	Share	Filers	Change
Hedge funds	28.1%	4	+3.6%
Venture capital funds	25.5%	1	0.0%
Mixed private funds	38.2%	1	0.0%
Private funds, type not stated	0.0%	0	—
No private funds	0.0%	0	—
Unknown	8.2%	3	0.0%

Location	Share	Filers	Change	New	Exited
United States	99.5%	7	+1.0%	0	0
Outside the US	0.5%	2	+0.7%	0	0

How the mix is measured

Shares are 13F common shares restated to today's split basis; options and principal amounts are left out. The change compares only filers with a 13F in both quarters and keeps each filer in its bucket of the later quarter on both sides; a filer that continues under a new CIK is compared through its successor. Holder type comes from each filer's current regulatory profile; client base and private funds come from the Form ADV roster current at each quarter end (rosters from December 2019, so an earlier quarter reads Unknown). Style, turnover, horizon and book size are measured from each filer's 13F book in the newest measured quarter, and Not measured means none was. Actively managed books are those measured systematic-like, concentrated or diversified active.

Conviction and Crowding

9 13F filers, quarter ended Jun 30, 2026

Measured across every 13F filer's common-share book once the quarter's filing window closed. Crowding counts filers with high turnover or that advise private funds on Form ADV.

Conviction holders

33.3% of filers hold it in their top 10

Mar 31, 2026: 3

Holders above 5%

median weight 0.025%

Mar 31, 2026: 0

Crowding

—

shares outstanding is an issuer-wide count, not one listing's

Private-fund advisers

—

of shares outstanding

Institutional ownership

—

shares outstanding is an issuer-wide count, not one listing's

Top 10 holders

100.0%

of 13F shares, Herfindahl 0.257

Active holders

+1.0%

like-for-like share change of active filers

5% stakes on record

0 13D, 0 13G

How long holders have held it value-weighted 14.5 quarters

Under 1 year 2.34% 1 to 3 years 0.034% 3 years or more 97.6% Since coverage start 0.000%

Managers in the top fifth by current three-year FundScore alpha were net buyers of $0 (0 buying, 0 selling).

Estimated Holder Cost Basis

Quarter ended Jun 30, 2026, on that quarter's share basis

Estimated, never filed: each 13F buy is costed at its quarter's average traded price and each sale keeps the average cost, so this is what holders paid on average if they traded evenly through each quarter.

Estimated avg cost

$2.13

estimated per share

Mar 31, 2026: $1.94

Quarter-end price

$21.37

implied by 13F values

Estimated gain or loss

+902.3%

price against the estimated cost

Estimated at a loss

2.34%

of costed 13F value

Estimated cost covers 100.0% of the 13F shares; positions already held when a filer's 13F history starts, or bought in a quarter without a trusted average price, have no estimate.

Shared Holders

Companies NAMSW's active holders also own, quarter ended Jun 30, 2026

#	Company	Shared holders	Similarity
1	ORKA Oruka Therapeutics, Inc.	14	0.321
2	INSM INSMED Inc	17	0.290
3	COAG Hemab Therapeutics Holdings, Inc.	6	0.285
4	SION Sionna Therapeutics, Inc.	8	0.269
5	ELVN Enliven Therapeutics, Inc.	11	0.267
6	IRON Disc Medicine, Inc.	9	0.261
7	EQ Equillium, Inc.	5	0.259
8	XENE Xenon Pharmaceuticals Inc.	11	0.252
9	DMRA Damora Therapeutics, Inc.	7	0.245
10	SRRK Scholar Rock Holding Corp	9	0.241

Shareholder Targets

13F filers that own its peers but not NAMSW, quarter ended Jun 30, 2026

Found through its holder-overlap peers: ORKA, INSM, COAG, SION, ELVN, IRON, EQ, XENE, DMRA, SRRK, SYRE, DNTH, PTGX, MLYS, PHVS, ALKS, CRNX, PRAX, ERAS, PBLS. 884 filers in all.

#	Filer	In peers	Of book	Largest peers
1	VANGUARD CAPITAL MANAGEMENT LLC Registered adviser, Index-like	$4,022,177,783 19 held	0.090%	INSM, PRAX, ALKS
2	BAKER BROS. ADVISORS LP Registered adviser, Concentrated	$2,345,637,177 10 held	11.8%	INSM, PRAX, ALKS
3	RTW INVESTMENTS, LP Registered adviser, Diversified active	$2,255,771,753 8 held	19.3%	PTGX, INSM, SYRE
4	Driehaus Capital Management LLC Registered adviser, Diversified active	$1,428,761,216 11 held	8.28%	PRAX, XENE, SYRE
5	PERCEPTIVE ADVISORS LLC Registered adviser, Diversified active	$1,385,102,158 6 held	21.6%	PRAX, SYRE, ORKA
6	T. Rowe Price Investment Management, Inc. Adviser, Diversified active	$1,377,506,548 9 held	0.910%	ERAS, DNTH, INSM
7	Siren, L.L.C. Unknown, Diversified active	$1,341,814,202 12 held	27.2%	SRRK, ERAS, ELVN
8	Venrock Adviser, LLC Registered adviser, Concentrated	$1,240,205,413 7 held	37.6%	ORKA, ERAS, SYRE
9	FARALLON CAPITAL MANAGEMENT LLC Registered adviser, Diversified active	$1,179,438,578 3 held	6.96%	PTGX, CRNX, PBLS
10	Fairmount Funds Management LLC Registered adviser, Concentrated	$920,754,225 4 held	60.9%	ORKA, DNTH, DMRA

Quarterly Activity

vs Mar 31, 2026

New

Increased

Decreased

Sold Out

Unchanged

New and Sold Out count only filers that reported a 13F for both quarters: a first-time filer's book is not a buy, and a fund that has not filed, or withheld its positions under confidential treatment, has not sold.

Holder count: 0

Institutional value: +7.6%

Shares held: +0.9%

Top Buyers

vs Mar 31, 2026

Institution	Added	Now Holds	Open
Mid WOLVERINE ASSET MANAGEMENT LLC	+12,798	14,925
Mega UBS Group AG	+47	443

Top Sellers

vs Mar 31, 2026

No qualifying movers this quarter.

Filter: New 0 Increased 2 Reduced 0 Sold out 0 Unchanged 8

Holder type: Registered adviser 7 Bank 1 Unknown 2

Showing 10 of 10

All Common Calls Puts

Compact Export CSV

Holder

Value (USD)

% of 13F

Frazier Life Sciences Management, L.P. NAMSW

$10,692,116

36.15%

500,333

RA CAPITAL MANAGEMENT, L.P. NAMSW

$7,123,326

24.08%

333,333

Affinity Asset Advisors, LLC NAMSW

$5,235,650

17.70%

245,000

Bain Capital Life Sciences Investors, LLC NAMSW

$2,136,978

7.22%

99,999

DEERFIELD MANAGEMENT COMPANY, L.P. NAMSW

$1,982,858

6.70%

92,787

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Deerfield UGP, LLC	92,787	$1,982,858	100.0%	Defined

MILLENNIUM MANAGEMENT LLC NAMSW

$1,602,750

5.42%

75,000

ARISTEIA CAPITAL, L.L.C. NAMSW

$335,679

1.13%

15,708

WOLVERINE ASSET MANAGEMENT LLC NAMSW

$318,947

1.08%

14,925

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Wolverine Holdings, LLC	14,925	$318,947	100.0%	Defined

Vestcor Inc NAMSW

$142,452

0.48%

6,666

UBS Group AG NAMSW

$9,466

0.03%

443

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
UBS Securities LLC	443	$9,466	100.0%	Defined

Key facts CIK 1936258 CUSIP N62509109 Visit website Investor relations