Atossa Therapeutics, Inc.

ATOS • NASDAQ

Atossa Therapeutics, Inc. is a biotechnology company in the healthcare sector on NASDAQ, led by Steven C. Quay, with a market cap of $106.6M. As of Q3 2025, 15% of shares are held by 64 institutional investors, with VANGUARD GROUP INC as the largest holder at 4.71%.

Chairman of the Board, President and Chief Executive OfficerSteven C. Quay

Market Cap$106.6M

Biotechnology

Healthcare

Employees10.0

Websiteatossatherapeutics.com

Country

United States of America

Overview

Overview of institutional ownership in ATOS as of Q3 2025 with a market cap of $112.0M

All Institutions

Institutions: 64
Value Held: $16.8M
Shares Held: 19.4M
Avg Position: $262.6K
Median Position: $17.1K

Hedge Funds

Hedge Funds: 7
Value Held: $3.7M
Shares Held: 4.2M
Avg Position: $523.5K
Median Position: $228.3K

Ownership Breakdown

Institutional (non-HF)

11.73%

$13.1M

Hedge Funds

3.27%

$3.7M

Retail & Other

84.99%

$95.2M

Based on market cap of $112.0M as of Q3 2025. Institutional (non-HF) excludes hedge funds to avoid double counting.

Biggest Investors

Institutions with the largest positions in ATOS as of Q3 2025

Institution	Key People	Position Value	Ownership	Owned Since	Total AUM (Long)
VANGUARD GROUP INC Institution	Salim Ramji CEO	$5.3M 0.00% of portfolio	4.71% 6.1M shares	Q1 2014 Held for 11y 8m	$6.69T
AMERIPRISE FINANCIAL INC Institution	Jim Cracchiolo CEO	$2.6M 0.00% of portfolio	2.28% 3.0M shares	Q2 2025 Held for 5 months	$433.11B
B BlackRock, Inc. Institution	-	$1.7M 0.00% of portfolio	1.55% 2.0M shares	Q1 2017 Held for 8y 8m	$5.67T
MILLENNIUM MANAGEMENT LLC Hedge Fund•Multi-Strategy	Dan Michael Berkovitz Chairman	$1.4M 0.00% of portfolio	1.29% 1.7M shares	Q2 2021 Held for 4y 5m	$121.98B
RENAISSANCE TECHNOLOGIES LLC Hedge Fund•Quant	Peter Fitzhugh Brown CEO	$1.3M 0.00% of portfolio	1.20% 1.5M shares	Q4 2021 Held for 3y 11m	$75.8B
GEODE CAPITAL MANAGEMENT LLC ETF Provider	David Kenneth Lane CEO	$1.2M 0.00% of portfolio	1.05% 1.4M shares	Q1 2018 Held for 7y 8m	$1.57T
STATE STREET CORP Institution	Ronald P. O'Hanley CEO	$394.0K 0.00% of portfolio	0.35% 454.5K shares	Q2 2021 Held for 4y 5m	$2.88T
GSA CAPITAL PARTNERS LLP Hedge Fund•Quant	David Khabie-Zeitoune CEO	$269.4K 0.02% of portfolio	0.24% 310.8K shares	Q2 2025 Held for 5 months	$1.1B
NORTHERN TRUST CORP Institution	Michael G. O'Grady CEO	$228.3K 0.00% of portfolio	0.20% 263.4K shares	Q3 2019 Held for 6y 2m	$782.01B
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	Kenneth Cordele Griffin CEO	$228.3K 0.00% of portfolio	0.20% 263.4K shares	Q4 2018 Held for 6y 11m	$122.08B

Net Capital Flow

Institutional buying and selling activity for ATOS in Q3 2025

Traded: −$1.6M
Buyers: 22
Sellers: 48
Total Bought: +$1.2M
Total Sold: −$2.8M
Avg Position: $182.7K

Biggest Buyers

Institution	Net Bought	Current Position
GSA CAPITAL PARTNERS LLP Hedge Fund•Quant	+$225.2K +259.7K shares	$269.4K 310.8K shares
VANGUARD GROUP INC Institution	+$213.0K +245.7K shares	$5.3M 6.1M shares
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	+$153.0K +176.5K shares	$228.3K 263.4K shares
Graham Capital Management, L.P. Hedge Fund•Multi-Strategy	+$143.4K +165.4K shares	$143.4K 165.4K shares
ACADIAN ASSET MANAGEMENT LLC Long Only Manager	+$84.3K +97.3K shares	$84.3K 97.3K shares
S Squarepoint Ops LLC Hedge Fund•Quant	+$62.6K +72.2K shares	$219.6K 253.3K shares
Marshall Wace LLP Institution	+$62.4K +71.7K shares	$74.0K 85.1K shares
GEODE CAPITAL MANAGEMENT LLC ETF Provider	+$53.7K +61.9K shares	$1.2M 1.4M shares
BANK OF AMERICA CORP /DE/ Institution	+$48.2K +55.6K shares	$134.5K 155.2K shares
Connor, Clark & Lunn Investment Management Ltd. Long Only Manager	+$43.3K +49.9K shares	$215.5K 248.6K shares

Biggest Sellers

Institution	Net Sold	Current Position
MILLENNIUM MANAGEMENT LLC Hedge Fund•Multi-Strategy	−$328.5K −378.9K shares	$1.4M 1.7M shares
Y Y-Intercept Ltd Institution	−$320.7K −386.3K shares	Sold Off 0 shares
GOLDMAN SACHS GROUP INC Institution	−$278.0K −335.0K shares	Sold Off 0 shares
J JANE STREET GROUP, LLC Institution	−$256.9K −296.3K shares	$140.8K 162.4K shares
Q Qube Research & Technologies Ltd Institution	−$240.8K −277.7K shares	$120.2K 138.6K shares
RENAISSANCE TECHNOLOGIES LLC Hedge Fund•Quant	−$228.5K −263.6K shares	$1.3M 1.5M shares
UBS Group AG Institution	−$131.6K −151.7K shares	$226.0K 260.7K shares
B BlackRock, Inc. Institution	−$130.4K −150.4K shares	$1.7M 2.0M shares
Aster Capital Management Ltd RIA/Wealth	−$120.2K −144.9K shares	Sold Off 0 shares
Jain Global LLC Hedge Fund•Multi-Strategy	−$92.2K −106.3K shares	$14.5K 16.7K shares

Entry and Exit Activity

Institutions that initiated new positions or completely exited ATOS in Q3 2025

New Positions: 3
New Value: $23.4K
Exited Positions: 25
Exited Value: $1.1M

New Positions

Institution	Position Value
Sigma Planning Corp RIA/Wealth	$20.8K 24.0K shares
H HUNTINGTON NATIONAL BANK Long Only Manager	$2.6K 3.0K shares
SRS Capital Advisors, Inc. RIA/Wealth	$36.0 42.0 shares

Exited Positions

Institution	Previous Position
Y Y-Intercept Ltd Institution	$320.7K 386.3K shares
GOLDMAN SACHS GROUP INC Institution	$278.0K 335.0K shares
Aster Capital Management Ltd RIA/Wealth	$120.2K 144.9K shares
H HSBC HOLDINGS PLC Institution	$68.6K 77.9K shares
C Catalyst Funds Management Pty Ltd Institution	$49.2K 59.3K shares
AQR CAPITAL MANAGEMENT LLC Hedge Fund•Multi-Strategy	$40.1K 48.3K shares
V Virtu Financial LLC Institution	$30.5K 36.8K shares
TWO SIGMA ADVISERS, LLC Hedge Fund•Multi-Strategy	$28.4K 34.2K shares
Hudson Bay Capital Management LP Hedge Fund•Multi-Strategy	$25.9K 31.2K shares
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	$22.5K 27.2K shares

Options Activity

Institutions with the largest Call and Put options positions in ATOS as of Q3 2025

Call Positions: 3
Call Value: $69.2K
Put Positions: 3
Put Value: $85.9K

Call Positions

Institution	Position Value
W WOLVERINE TRADING, LLC Institution	$23.8K 273.0 contracts
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$23.5K 270.0 contracts
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$21.8K 252.0 contracts

Put Positions

Institution	Position Value
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$32.3K 371.0 contracts
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$29.2K 337.0 contracts
W WOLVERINE TRADING, LLC Institution	$24.4K 280.0 contracts

Most Committed Institutions

Institutions with ATOS as the highest % of their portfolio as of Q3 2025

Institution	Key People	Portfolio Weight	Ownership	Owned Since	Total AUM (Long)
GSA CAPITAL PARTNERS LLP Hedge Fund•Quant	David Khabie-Zeitoune CEO	0.02% $269.4K	0.24% 310.8K shares	Q2 2025 Held for 5 months	$1.1B
G Gallagher Capital Advisors, LLC RIA/Wealth	John Robert Gallagher Managing Partner	0.02% $27.5K	0.02% 31.6K shares	Q4 2024 Held for 11 months	$173.7M
Graham Capital Management, L.P. Hedge Fund•Multi-Strategy	Brian Kevin Douglas CEO	0.01% $143.4K	0.13% 165.4K shares	Q3 2025 Held for 2 months	$1.8B
P Point72 Asia Pte. Ltd. Institution	-	0.01% $38.2K	0.03% 44.1K shares	Q2 2025 Held for 5 months	$645.8M
LVM CAPITAL MANAGEMENT LTD/MI RIA/Wealth	Craig Alan Vander Molen President	0.00% $18.2K	0.02% 21.0K shares	Q2 2023 Held for 2y 5m	$1.0B
RENAISSANCE TECHNOLOGIES LLC Hedge Fund•Quant	Peter Fitzhugh Brown CEO	0.00% $1.3M	1.20% 1.5M shares	Q4 2021 Held for 3y 11m	$75.8B
MILLENNIUM MANAGEMENT LLC Hedge Fund•Multi-Strategy	Dan Michael Berkovitz Chairman	0.00% $1.4M	1.29% 1.7M shares	Q2 2021 Held for 4y 5m	$121.98B
X XTX Topco Ltd Institution	-	0.00% $21.5K	0.02% 24.8K shares	Q2 2023 Held for 2y 5m	$1.9B
P PFG Investments, LLC Institution	-	0.00% $18.4K	0.02% 21.3K shares	Q1 2024 Held for 1y 8m	$1.9B
J. L. Bainbridge & Co., Inc. RIA/Wealth	Jerry Lee Bainbridge CEO	0.00% $9.6K	0.01% 11.1K shares	Q2 2021 Held for 4y 5m	$1.1B