HOWL · Werewolf Therapeutics, Inc. · Holdings

$1.04 +0.00 (+0.00%)

Market Cap

$50.54M

48.60M

Volume · Oct 20 343.87K Avg daily vol (3M) 6.69M

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 HOWL: 13F, 13D and 13G, insiders and funds →

Institutional holdings are being reconciled with SEC filings. Holder totals and changes may be incomplete until reconciliation finishes.

The Sep 30, 2026 filing window is still open — showing the latest known positions. Funds that have not filed yet carry their prior-quarter positions; a fund that filed without this stock counts as sold out. Each fund's Change is measured against its own previous reported quarter, shown in the Reported column. Pick a completed quarter in the Quarter selector below to put every fund on one quarter and see the stock-wide activity breakdown.

Quarter:

Holders: 48

Total Value: $4,048,378

Total Shares: 11,068,389

Institutional Ownership Trend

22 quarters

Holder Concentration

Across 46 13F filers

Top Holder

21.8%

of institutional value

Top 5

61.4%

of institutional value

Top 10

81.6%

of institutional value

HHI

1,053

Broadly held

Who Holds HOWL

Last 8 quarters through Sep 30, 2026 (filing window open)

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, the newest closed quarter: 45 filers, like-for-like change -22.4%; actively managed books -27.1%; index-like books -4.0%.

Holder type	Share	Filers	Change	New	Exited
Registered adviser	69.5%	19	-27.6%	6	7
Exempt adviser	5.8%	1	0.0%	0	0
Adviser	0.7%	1	-93.4%	0	0
Bank	6.9%	6	+34.6%	0	1
Broker-dealer	0.1%	2	+15.1%	0	0
Non-US	0.0%	2	+2.3%	0	0
Holding company	1.4%	4	-18.1%	0	1
Insurer	0.0%	0	—	0	0
Benefit plan	0.0%	0	—	0	0
Unknown	15.6%	10	+72.8%	3	3

Style	Share	Filers	Change	New	Exited
Index-like	18.9%	8	-4.0%	0	0
Systematic-like	21.9%	9	+744.5%	5	1
Concentrated	28.7%	6	-60.7%	2	2
Diversified active	25.1%	21	-11.1%	2	9
Unknown	5.4%	1	0.0%	0	0
Not measured	0.0%	0	—	0	0

Turnover	Share	Filers	Change	New	Exited
Low turnover	37.5%	20	-51.6%	1	4
Medium turnover	22.0%	9	-25.0%	2	4
High turnover	24.6%	13	+545.1%	6	2
Unknown	15.9%	3	-12.9%	0	2
Not measured	0.0%	0	—	0	0

Holding horizon	Share	Filers	Change	New	Exited
Short horizon	20.0%	7	+6.8%	3	2
Medium horizon	7.8%	7	-57.9%	1	1
Long horizon	48.9%	26	-42.4%	3	8
Unknown	23.3%	5	+245.5%	2	1
Not measured	0.0%	0	—	0	0

13F book size	Share	Filers	Change	New	Exited
Under $1B	21.6%	8	-6.2%	2	3
$1B to $10B	4.6%	13	-64.8%	4	1
$10B to $100B	46.6%	7	-30.9%	2	2
$100B or more	27.2%	17	+7.0%	1	6
Not measured	0.0%	0	—	0	0

Client base	Share	Filers	Change	New	Exited
Individuals and high net worth	0.7%	7	-10.7%	1	3
Pooled investment vehicles	54.5%	10	-26.9%	5	2
Registered funds and BDCs	14.3%	2	-7.8%	0	1
Pension and profit sharing plans	0.0%	0	—	0	0
Insurance companies	0.0%	0	—	0	0
Governments and sovereign funds	0.0%	0	—	0	0
Diversified	0.0%	0	—	0	0
Unknown	30.5%	26	-19.8%	3	6

Private funds	Share	Filers	Change	New	Exited
Hedge funds	38.2%	10	+60.2%	5	2
Venture capital funds	22.0%	1	-64.3%	0	0
Mixed private funds	0.0%	0	—	0	0
No private funds	15.0%	9	-4.3%	1	3
Real estate funds	0.0%	0	-100.0%	0	1
Other private funds	0.0%	0	-100.0%	0	1
Private funds, type not stated	0.0%	0	—	0	0
Securitized asset funds	0.0%	0	—	0	0
Unknown	24.7%	25	-8.6%	3	5

Location	Share	Filers	Change	New	Exited
United States	89.4%	38	-26.7%	8	12
Outside the US	10.6%	7	+52.3%	1	0

The Sep 30, 2026 filing window is still open, so its bar carries the Jun 30, 2026 positions of filers that have not filed yet.

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

45 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

2.22% of filers hold it in their top 10

Mar 31, 2026: 1

Holders above 5%

median weight 0.000%

Mar 31, 2026: 1

Crowding

14.7%

of shares outstanding, 43rd percentile

Mar 31, 2026: 19.6%

Private-fund advisers

13.5%

of shares outstanding

Institutional ownership

22.4%

27.9% of the estimated free float

Top 10 holders

82.3%

of 13F shares, Herfindahl 0.107

Active holders

-27.1%

like-for-like share change of active filers

5% stakes on record

0 13D, 3 13G (0 institutional, 1 passive, 0 exempt)

How long holders have held it value-weighted 11.6 quarters

Under 1 year 44.3% 1 to 3 years 4.02% 3 years or more 51.7% 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

$4.60

estimated per share

Mar 31, 2026: $8.11

Quarter-end price

$0.36

implied by 13F values

Estimated gain or loss

-92.2%

price against the estimated cost

Estimated at a loss

100.0%

of costed 13F value

Estimated cost covers 81.9% 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 HOWL's active holders also own, quarter ended Jun 30, 2026

#	Company	Shared holders	Similarity
1	BIOA BioAge Labs, Inc.	3	0.254
2	TSHA Taysha Gene Therapies, Inc.	3	0.224
3	AVTX Avalo Therapeutics, Inc.	3	0.215

Shareholder Targets

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

Found through its holder-overlap peers: BIOA, TSHA, AVTX. 264 filers in all.

#	Filer	In peers	Of book	Largest peers
1	Avoro Capital Advisors LLC Registered adviser, Concentrated	$205,803,320 2 held	1.85%	TSHA, AVTX
2	FMR LLC Holding company, Diversified active	$189,572,091 3 held	0.010%	AVTX, TSHA, BIOA
3	Vestal Point Capital, LP Registered adviser, Diversified active	$146,538,150 2 held	3.42%	TSHA, AVTX
4	Octagon Capital Advisors LP Registered adviser, Concentrated	$108,854,471 2 held	9.99%	TSHA, BIOA
5	RTW INVESTMENTS, LP Registered adviser, Diversified active	$95,579,356 2 held	0.820%	TSHA, AVTX
6	a16z Capital Management, L.L.C. Registered adviser, Concentrated	$79,244,996 1 held	0.560%	BIOA
7	Siren, L.L.C. Unknown, Diversified active	$67,055,202 1 held	1.36%	TSHA
8	Deep Track Capital, LP Adviser, Diversified active	$66,712,800 1 held	1.02%	AVTX
9	Affinity Asset Advisors, LLC Registered adviser, Diversified active	$65,509,500 2 held	3.30%	AVTX, TSHA
10	FARALLON CAPITAL MANAGEMENT LLC Registered adviser, Diversified active	$61,485,540 2 held	0.360%	AVTX, TSHA

Fund Ownership of HOWL by Fund Type

Registered funds' Form N-PORT reports for the quarter ended Jun 30, 2026

Index funds and index ETFs hold 3.20% of shares outstanding.

Fund type	Of shares outstanding	Change	Shares	Funds
Index funds	0.69%	+0.12 pp	335,197	4
Index ETFs	2.51%	0.00 pp	1,217,976	2
Active ETFs	0.00%	0.00 pp	0	0
Active funds	0.00%	-0.15 pp	653	2
Unclassified	0.00%	0.00 pp	0	0
All registered funds	3.20%	-0.04 pp	1,553,826	8

How fund types are measured

Each fund series counts once, with its latest Form N-PORT report dated inside the quarter; only long share positions count, restated to today's split basis. The fund type is the series' latest Form N-CEN answer on or before the quarter end (the index-fund box and the exchange-traded flag), never its name. Unclassified funds have no usable N-CEN; unit investment trusts are among them, so index ownership is a floor. Funds sit inside their advisers' 13F reports, so these shares overlap the 13F figures and are never added to them.

Holder type: Registered adviser 20 Exempt adviser 1 Adviser 1 Bank 6 Broker-dealer 2 Non-US 2 Holding company 4 Unknown 12

Showing 49 of 49

All Common Calls Puts

Compact Export CSV

Holder

Value (USD)

% of 13F

RA CAPITAL MANAGEMENT, L.P.

$859,587

21.23%

2,387,744

Balyasny Asset Management L.P.

$644,432

15.92%

1,790,089

VANGUARD CAPITAL MANAGEMENT LLC

$438,471

10.83%

1,217,976

RENAISSANCE TECHNOLOGIES LLC

$242,867

6.00%

674,632

Lynx1 Capital Management LP

$236,802

5.85%

657,786

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

Manager	Shares	Value (USD)	% of position	Discretion
Lynx1 Capital Advisors LLC	657,786	$236,802	100.0%	Other

SPHERA FUNDS MANAGEMENT LTD.

$225,651

5.57%

626,810

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

Manager	Shares	Value (USD)	% of position	Discretion
Sphera Global Healthcare Management LP joint	626,810	$225,651	100.0%	Defined

DC Funds, LP

$212,076

5.24%

589,102

Verdad Advisers, LP

$125,535

3.10%

348,709

GEODE CAPITAL MANAGEMENT, LLC

$120,893

2.99%

335,815

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

Manager	Shares	Value (USD)	% of position	Discretion
GEODE CAPITAL MANAGEMENT TRUST COMPANY, LLC	62,051	$22,338	18.5%	Defined
Held directly	273,764	$98,555	81.5%	Defined

BANK OF AMERICA CORP /DE/

$112,140

2.77%

311,502

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

Manager	Shares	Value (USD)	% of position	Discretion
BANK OF AMERICA NA	23,206	$8,354	7.4%	Defined
MERRILL LYNCH, PIERCE, FENNER & SMITH INC.	288,296	$103,786	92.6%	Defined

XTX Topco Ltd

$97,732

2.41%

271,478

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

Manager	Shares	Value (USD)	% of position	Discretion
XTX EXECUTION SERVICES LLC joint	271,478	$97,732	100.0%	Defined

JANE STREET GROUP, LLC

$90,661

2.24%

251,837

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

Manager	Shares	Value (USD)	% of position	Discretion
Jane Street Capital, LLC	146,573	$52,766	58.2%	Defined
Jane Street Global Trading, LLC	105,264	$37,895	41.8%	Defined

UBS Group AG

$77,700

1.92%

215,838

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

Manager	Shares	Value (USD)	% of position	Discretion
UBS AG	102	$36	0.0%	Defined
UBS Europe SE	215,736	$77,664	100.0%	Defined

VANGUARD FIDUCIARY TRUST CO

$56,781

1.40%

157,726

Vontobel Holding Ltd.

$55,338

1.37%

60,000

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

Manager	Shares	Value (USD)	% of position	Discretion
BANK VONTOBEL AG	60,000	$55,338	100.0%	Defined

Vilga Financial Planning LLC

$49,272

1.22%

53,423

STATE STREET CORP

$42,900

1.06%

119,168

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

Manager	Shares	Value (USD)	% of position	Discretion
STATE STREET GLOBAL ADVISORS TRUST COMPANY	119,168	$42,900	100.0%	Defined

Squarepoint Ops LLC

$37,167

0.92%

103,242

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

Manager	Shares	Value (USD)	% of position	Discretion
Squarepoint Capital LLP	103,242	$37,167	100.0%	Defined

BlackRock, Inc.

$36,566

0.90%

101,573

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

Manager	Shares	Value (USD)	% of position	Discretion
BLACKROCK FINANCIAL MANAGEMENT INC/DE	29,623	$10,664	29.2%	Sole
BlackRock Investment Management, LLC	250	$90	0.2%	Sole
BlackRock Institutional Trust Company, N.A.	71,700	$25,812	70.6%	Sole

Rangeley Capital, LLC

$36,000

0.89%

100,000

NORTHERN TRUST CORP

$31,266

0.77%

86,851

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

Manager	Shares	Value (USD)	% of position	Discretion
NORTHERN TRUST CO joint	86,851	$31,266	100.0%	Defined

Alyeska Investment Group, L.P.

$31,159

0.77%

86,554

MPM BIOIMPACT LLC

$28,851

0.71%

80,142

CITADEL ADVISORS LLC

$27,000

0.67%

75,000

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

Manager	Shares	Value (USD)	% of position	Discretion
Citadel Securities GP LLC	75,000	$27,000	100.0%	Defined

MILLENNIUM MANAGEMENT LLC

$22,339

0.55%

62,055

Virtu Financial LLC

$16,368

0.40%

45,467

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

Manager	Shares	Value (USD)	% of position	Discretion
Virtu Americas LLC	45,467	$16,368	100.0%	Defined

TWO SIGMA INVESTMENTS, LP

$9,828

0.24%

27,300

GSA CAPITAL PARTNERS LLP

$9,772

0.24%

27,146

GOLDMAN SACHS GROUP INC

$7,208

0.18%

20,023

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

Manager	Shares	Value (USD)	% of position	Discretion
GOLDMAN SACHS & CO. LLC	20,023	$7,208	100.0%	Defined

StoneX Group Inc.

$7,200

0.18%

20,000

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

Manager	Shares	Value (USD)	% of position	Discretion
STONEX FINANCIAL INC.	20,000	$7,200	100.0%	Defined

MORGAN STANLEY

$6,878

0.17%

19,108

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

Manager	Shares	Value (USD)	% of position	Discretion
MORGAN STANLEY & CO. LLC	1,885	$678	9.9%	Defined
MORGAN STANLEY CAPITAL SERVICES, LLC	17,223	$6,200	90.1%	Defined

CITADEL ADVISORS LLC

$5,580

0.14%

15,500

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

Manager	Shares	Value (USD)	% of position	Discretion
Citadel Securities GP LLC	15,500	$5,580	100.0%	Defined

CERTUITY, LLC

$5,400

0.13%

15,000

BARCLAYS PLC

$4,764

0.12%

13,235

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

Manager	Shares	Value (USD)	% of position	Discretion
BARCLAYS BANK PLC	13,235	$4,764	100.0%	Defined

HBK Sorce Advisory LLC

$4,761

0.12%

13,227

Larson Financial Group LLC

$4,698

0.12%

13,052

LPL Financial LLC

$4,244

0.10%

11,791

Ranch Capital Advisors Inc.

$3,960

0.10%

11,000

Marest Capital, LLC

$3,913

0.10%

10,870

Cetera Investment Advisers

$3,672

0.09%

10,200

Tower Research Capital LLC (TRC)

$3,562

0.09%

9,897

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

Manager	Shares	Value (USD)	% of position	Discretion
Latour Trading LLC (Latour)	9,897	$3,562	100.0%	Defined

OSAIC HOLDINGS, INC.

$3,105

0.08%

8,625

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

Manager	Shares	Value (USD)	% of position	Discretion
OSAIC WEALTH, INC.	8,575	$3,087	99.4%	Defined
Osaic Advisory Services, LLC	50	$18	0.6%	Defined

Financial Perspectives, Inc

$2,430

0.06%

6,750

JPMORGAN CHASE & CO

$758

0.02%

2,108

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

Manager	Shares	Value (USD)	% of position	Discretion
J.P. Morgan Securities LLC	1,177	$423	55.8%	Defined
J.P. Morgan Securities plc	931	$335	44.2%	Defined

GROUP ONE TRADING LLC

$673

0.02%

1,871

BNP PARIBAS ARBITRAGE, SA

$284

0.01%

790

SIMPLEX TRADING, LLC

$91

0.00%

255

SBI Securities Co., Ltd.

$36

0.00%

100

Optiver Holding B.V.

0.00%

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

Manager	Shares	Value (USD)	% of position	Discretion
Optiver VOF	22	$7	100.0%	Defined

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