Offerings // ATOSSA THERAPEUTICS, INC.

ATOS offering history

Every offering-related filing in ATOSSA THERAPEUTICS, INC.’s recent SEC record — registrations (announced capacity) kept separate from pricing documents (executed sales). Reviewed 641 filings back to Mar 30, 2010.

Last executed offering

Jun 12, 2026

424B5 — priced deal (shares or notes)

Last registration (announced)

May 13, 2024

S-3 — capacity, not a sale

Executed, last 12 months

424B pricings + 8-K 3.02 sales

Registered, last 12 months

S-1/S-3/F-series registrations

Date	Filing		What it means
Jun 12, 2026	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Feb 20, 2026	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Feb 20, 2026	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Nov 19, 2024	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
May 23, 2024	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
May 13, 2024	S-3 →	REGISTERED	S-3 registration — capacity to sell shares, not a sale yet
Apr 29, 2021	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Apr 21, 2021	S-3 →	REGISTERED	S-3 registration — capacity to sell shares, not a sale yet
Mar 23, 2021	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Mar 22, 2021	S-3MEF →	REGISTERED	S-3MEF registration — capacity to sell shares, not a sale yet
Feb 4, 2021	424B2 →	EXECUTED	Prospectus supplement priced — shares or notes (large filers: often a bond deal)
Jan 29, 2021	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Jan 22, 2021	S-3 →	REGISTERED	S-3 registration — capacity to sell shares, not a sale yet
Jan 8, 2021	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Dec 21, 2020	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Dec 11, 2020	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Dec 8, 2020	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Dec 1, 2020	S-1/A →	REGISTERED	S-1/A registration — capacity to sell shares, not a sale yet
Nov 20, 2020	S-1 →	REGISTERED	S-1 registration — capacity to sell shares, not a sale yet
Sep 25, 2020	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Sep 10, 2020	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Sep 2, 2020	S-3 →	REGISTERED	S-3 registration — capacity to sell shares, not a sale yet
Feb 7, 2020	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Jun 14, 2018	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Jun 4, 2018	S-1 →	REGISTERED	S-1 registration — capacity to sell shares, not a sale yet
May 16, 2018	FWP →	MARKETING	Free-writing prospectus — offering being marketed
May 10, 2018	424B4 →	EXECUTED	Final prospectus — offering priced (typical for IPOs and marketed share deals)
May 9, 2018	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
May 3, 2018	S-1/A →	REGISTERED	S-1/A registration — capacity to sell shares, not a sale yet
Apr 23, 2018	S-1/A →	REGISTERED	S-1/A registration — capacity to sell shares, not a sale yet
Mar 27, 2018	S-1 →	REGISTERED	S-1 registration — capacity to sell shares, not a sale yet
Dec 22, 2017	8-K →	EXECUTED	Unregistered share sale disclosed (8-K item 3.02)
Dec 21, 2017	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Oct 27, 2017	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Oct 26, 2017	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Oct 5, 2017	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Sep 22, 2017	S-3 →	REGISTERED	S-3 registration — capacity to sell shares, not a sale yet
Jul 3, 2017	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Mar 31, 2017	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Mar 30, 2017	FWP →	MARKETING	Free-writing prospectus — offering being marketed

ATOS offering-related filings from SEC EDGAR, newest first (capped at 40). Each links to the original document.

Two honest limits. (1) A 424B takedown can price shares or notes — EDGAR’s metadata doesn’t say which, so open the document: large investment-grade filers use these mostly for bond deals (no dilution), small-caps mostly for shares. (2) At-the-market (ATM) programs sell shares gradually and individual sales are not separately filed — the visible footprint is the enabling shelf and its 424B5; actual ATM share counts surface later in the 10-Q/10-K share count. Educational information from public filings, not investment advice.

Is a shelf active now? →Do they need money? →Red flags →Full ATOS workspace →

ATOS offering FAQ

When did ATOS last execute an offering?

Per SEC filings, ATOSSA THERAPEUTICS, INC.'s most recent priced offering document is a 424B5 filed 2026-06-12. Note a 424B takedown can price shares or notes (debt) — the linked document says which.

When did ATOS last announce or register an offering?

The most recent registration is a S-3 filed 2024-05-13. A registration is capacity to sell shares — not a sale.

Does an offering always mean dilution?

Registered direct offerings and shelf takedowns issue new shares and dilute existing holders. Resale registrations (424B3/B7) let existing holders sell and do not create new shares. Secondary sales by insiders also do not dilute. Each row here is labeled with what it is.

Free to use. No account, no card.