ATOSSA THERAPEUTICS INC ATOS
COM · Common Stock · CUSIP 04962H704
Company in Seattle, United States
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersSeattle, WA
- Founded2009
- Websiteatossatherapeutics.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once. Holder counts are more reliable. Shares outstanding: 10.0m as of 2026-07-31, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $1.93. Options: 3 managers hold calls ($115.9k notional), 1 hold puts ($2.9k).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q2 2025 | 1 |
| Q3 2025 | 0 |
| Q4 2025 | 1 |
| Q1 2026 | 33 |
| Q2 2026 | 32 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2025 | 0 | 1 |
| Q4 2025 | 1 | 0 |
| Q1 2026 | 30 | 1 |
| Q2 2026 | 15 | 15 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $0 | $0 | — |
| Q4 2025 | $0 | $0 | — |
| Q1 2026 | $459.2k | $571.8k | 1.25 |
| Q2 2026 | $115.9k | $2.9k | 0.02 |
Biggest buyers
| JANE STREET GROUP, LLC | New | +56.6k |
| BlackRock, Inc. | Added | +31.2k |
| RENAISSANCE TECHNOLOGIES LLC | Added | +23.0k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | New | +15.6k |
| VANGUARD CAPITAL MANAGEMENT LLC | Added | +12.7k |
| AMERIPRISE FINANCIAL INC | Added | +3.1k |
| ROYAL BANK OF CANADA | Added | +1.4k |
| MCF Advisors LLC | New | +1.1k |
| NORTHERN TRUST CORP | Added | +1.0k |
| VANGUARD FIDUCIARY TRUST CO | Added | +348 |
Biggest sellers
| MILLENNIUM MANAGEMENT LLC | Reduced | -20.2k |
| UBS Group AG | Reduced | -9.4k |
| GEODE CAPITAL MANAGEMENT, LLC | Reduced | -4.7k |
| MORGAN STANLEY | Reduced | -3.9k |
| Tower Research Capital LLC (TRC) | Sold out | -863 |
| GROUP ONE TRADING LLC | Reduced | -555 |
| NewEdge Advisors, LLC | Sold out | -333 |
| Avion Wealth | Sold out | -318 |
| Robinswood Financial LLC | Sold out | -170 |
| North Star Investment Management Corp. | Sold out | -80 |
Biggest calls
| SIMPLEX TRADING, LLC | Reduced | $89.0k48.3k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | New | $21.8k11.3k shares |
| GROUP ONE TRADING LLC | Reduced | $5.0k2.6k shares |
Biggest puts
| GROUP ONE TRADING LLC | Reduced | $2.9k1.5k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 1 | $7.0k | 0 | — | — |
| Q2 2025 | 1 | $9.9k | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 0 | — | — |
| Q1 2026 | 0 | — | 0 | — | — |
| Q2 2026 | 0 | — | 0 | — | — |
| Q3 2026 | 0 | — | 0 | — | — |
None reported since 1 Apr 2026.
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 361.7k $698.2k | Added +12.7k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 258.2k $498.4k | Added +3.1k |
| BlackRock, Inc. 0.00% of their portfolio | 164.4k $317.2k | Added +31.2k |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 132.0k $254.8k | Added +23.0k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 92.4k $178.3k | Reduced -4.7k |
| UBS Group AG 0.00% of their portfolio | 82.6k $159.5k | Reduced -9.4k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 56.6k $109.2k | New |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 52.6k $101.5k | Added +348 |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 46.5k $89.8k | Reduced -20.2k |
| STATE STREET CORP 0.00% of their portfolio | 39.8k $76.7k | Unchanged |
| NORTHERN TRUST CORP 0.00% of their portfolio | 20.2k $39.1k | Added +1.0k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 15.6k $30.1k | New |
| MORGAN STANLEY 0.00% of their portfolio | 12.3k $23.8k | Reduced -3.9k |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 3.1k $6.0k | Unchanged |
| JONES FINANCIAL COMPANIES LLLP 0.00% of their portfolio | 2.1k $3.9k | Unchanged |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 2.0k $4.0k | Added +1.4k |
| MCF Advisors LLC 0.00% of their portfolio | 1.1k $2.1k | New |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 587 $1.1k | Unchanged |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 390 $772 | Added +7 |
| Rockefeller Capital Management L.P. 0.00% of their portfolio | 333 $643 | Reduced -20 |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 228 $440 | Reduced -68 |
| SBI Securities Co., Ltd. 0.00% of their portfolio | 148 $286 | Added +35 |
| HARBOUR INVESTMENTS, INC. 0.00% of their portfolio | 110 $212 | Unchanged |
| TD Waterhouse Canada Inc. 0.00% of their portfolio | 103 $210 | Unchanged |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 87 $168 | Reduced -11 |
| GROUP ONE TRADING LLC 0.00% of their portfolio | 54 $104 | Reduced -555 |
| BESSEMER GROUP INC 0.00% of their portfolio | 6 $0 | New |
| Caitong International Asset Management Co., Ltd 0.00% of their portfolio | 6 $12 | New |
| Napier Financial, LLC 0.00% of their portfolio | 6 $12 | Unchanged |
| Bogart Wealth, LLC 0.00% of their portfolio | 5 $10 | Unchanged |
| Clearstead Advisors, LLC 0.00% of their portfolio | 4 $8 | Unchanged |
| FMR LLC 0.00% of their portfolio | 0 $0 | New |