Offerings // PROTHENA CORP PUBLIC LTD CO

PRTA offering history

Every offering-related filing in PROTHENA CORP PUBLIC LTD CO’s recent SEC record — registrations (announced capacity) kept separate from pricing documents (executed sales). Reviewed 1,002 filings back to Dec 17, 2012.

Last executed offering

Dec 16, 2022

424B5 — priced deal (shares or notes)

Last registration (announced)

Feb 22, 2024

S-3ASR — 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
Mar 2, 2026	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Feb 22, 2024	S-3ASR →	REGISTERED	Automatic shelf registration — effective immediately (large filers)
Dec 16, 2022	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Dec 13, 2022	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Dec 23, 2021	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
May 28, 2021	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Mar 24, 2021	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Mar 23, 2021	S-3ASR →	REGISTERED	Automatic shelf registration — effective immediately (large filers)
Mar 23, 2021	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Dec 12, 2019	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Nov 27, 2019	S-3/A →	REGISTERED	S-3/A registration — capacity to sell shares, not a sale yet
May 22, 2019	S-3 →	REGISTERED	S-3 registration — capacity to sell shares, not a sale yet
Mar 20, 2018	8-K →	EXECUTED	Unregistered share sale disclosed (8-K item 3.02)
Feb 26, 2018	S-3ASR →	REGISTERED	Automatic shelf registration — effective immediately (large filers)
Mar 6, 2017	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Mar 2, 2017	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Jan 7, 2016	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Jan 5, 2016	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Apr 8, 2015	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Apr 6, 2015	S-3ASR →	REGISTERED	Automatic shelf registration — effective immediately (large filers)
Apr 6, 2015	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Jun 25, 2014	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Jun 24, 2014	S-3MEF →	REGISTERED	S-3MEF registration — capacity to sell shares, not a sale yet
Jun 23, 2014	S-3ASR →	REGISTERED	Automatic shelf registration — effective immediately (large filers)
Jun 23, 2014	424B5 →	EXECUTED	Shelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Jan 29, 2014	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Jan 27, 2014	424B3 →	UPDATE	Prospectus update — often a resale registration, not necessarily new capital
Jan 24, 2014	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Jan 17, 2014	S-3 →	REGISTERED	S-3 registration — capacity to sell shares, not a sale yet
Oct 3, 2013	424B4 →	EXECUTED	Final prospectus — offering priced (typical for IPOs and marketed share deals)
Oct 2, 2013	S-1MEF →	REGISTERED	S-1MEF registration — capacity to sell shares, not a sale yet
Oct 2, 2013	EFFECT →	EFFECTIVE	SEC declared a registration effective — selling can begin
Sep 30, 2013	S-1/A →	REGISTERED	S-1/A registration — capacity to sell shares, not a sale yet
Sep 17, 2013	S-1 →	REGISTERED	S-1 registration — capacity to sell shares, not a sale yet
Dec 21, 2012	8-K →	EXECUTED	Unregistered share sale disclosed (8-K item 3.02)

PRTA 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 PRTA workspace →

PRTA offering FAQ

When did PRTA last execute an offering?

Per SEC filings, PROTHENA CORP PUBLIC LTD CO's most recent priced offering document is a 424B5 filed 2022-12-16. Note a 424B takedown can price shares or notes (debt) — the linked document says which.

When did PRTA last announce or register an offering?

The most recent registration is a S-3ASR filed 2024-02-22. 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.