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Offerings // MUSTANG BIO, INC.

MBIO offering history

Every offering-related filing in MUSTANG BIO, INC.’s recent SEC record — registrations (announced capacity) kept separate from pricing documents (executed sales). Reviewed 402 filings back to Jul 28, 2016.

Last executed offering
Sep 5, 2025
424B5 — priced deal (shares or notes)
Last registration (announced)
Feb 5, 2025
S-1/A — capacity, not a sale
Executed, last 12 months
1
424B pricings + 8-K 3.02 sales
Registered, last 12 months
0
S-1/S-3/F-series registrations
DateFilingWhat it means
Sep 5, 2025424B5 →EXECUTEDShelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Apr 11, 2025EFFECT →EFFECTIVESEC declared a registration effective — selling can begin
Apr 1, 2025424B3 →UPDATEProspectus update — often a resale registration, not necessarily new capital
Feb 27, 2025424B3 →UPDATEProspectus update — often a resale registration, not necessarily new capital
Feb 13, 2025424B3 →UPDATEProspectus update — often a resale registration, not necessarily new capital
Feb 7, 2025424B4 →EXECUTEDFinal prospectus — offering priced (typical for IPOs and marketed share deals)
Feb 5, 2025S-1/A →REGISTEREDS-1/A registration — capacity to sell shares, not a sale yet
Feb 5, 2025EFFECT →EFFECTIVESEC declared a registration effective — selling can begin
Jan 15, 2025S-1 →REGISTEREDS-1 registration — capacity to sell shares, not a sale yet
Dec 2, 2024424B3 →UPDATEProspectus update — often a resale registration, not necessarily new capital
Nov 27, 2024EFFECT →EFFECTIVESEC declared a registration effective — selling can begin
Nov 22, 2024S-3 →REGISTEREDS-3 registration — capacity to sell shares, not a sale yet
Oct 25, 20248-K →EXECUTEDUnregistered share sale disclosed (8-K item 3.02)
Aug 16, 2024424B5 →EXECUTEDShelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Jul 29, 2024EFFECT →EFFECTIVESEC declared a registration effective — selling can begin
Jul 19, 2024S-1 →REGISTEREDS-1 registration — capacity to sell shares, not a sale yet
Jul 3, 2024424B5 →EXECUTEDShelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Jun 24, 20248-K →EXECUTEDUnregistered share sale disclosed (8-K item 3.02)
Jun 21, 2024424B5 →EXECUTEDShelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Jun 20, 2024424B5 →EXECUTEDShelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Jun 12, 2024EFFECT →EFFECTIVESEC declared a registration effective — selling can begin
May 31, 2024S-3 →REGISTEREDS-3 registration — capacity to sell shares, not a sale yet
May 13, 2024424B3 →UPDATEProspectus update — often a resale registration, not necessarily new capital
May 1, 2024424B4 →EXECUTEDFinal prospectus — offering priced (typical for IPOs and marketed share deals)
Apr 29, 2024S-1/A →REGISTEREDS-1/A registration — capacity to sell shares, not a sale yet
Apr 29, 2024S-1/A →REGISTEREDS-1/A registration — capacity to sell shares, not a sale yet
Apr 29, 2024S-1/A →REGISTEREDS-1/A registration — capacity to sell shares, not a sale yet
Apr 29, 2024EFFECT →EFFECTIVESEC declared a registration effective — selling can begin
Apr 29, 2024EFFECT →EFFECTIVESEC declared a registration effective — selling can begin
Apr 2, 2024S-1/A →REGISTEREDS-1/A registration — capacity to sell shares, not a sale yet
Mar 15, 2024S-1 →REGISTEREDS-1 registration — capacity to sell shares, not a sale yet
Dec 12, 2023S-1 →REGISTEREDS-1 registration — capacity to sell shares, not a sale yet
Oct 30, 2023424B5 →EXECUTEDShelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Oct 30, 20238-K →EXECUTEDUnregistered share sale disclosed (8-K item 3.02)
Apr 14, 2023424B5 →EXECUTEDShelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
May 24, 2021EFFECT →EFFECTIVESEC declared a registration effective — selling can begin
May 20, 2021S-3/A →REGISTEREDS-3/A registration — capacity to sell shares, not a sale yet
Apr 23, 2021S-3 →REGISTEREDS-3 registration — capacity to sell shares, not a sale yet
Dec 31, 2020424B5 →EXECUTEDShelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
Dec 4, 2020424B5 →EXECUTEDShelf takedown priced — shares or notes (small-caps: usually shares; open the filing to confirm)
MBIO 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 MBIO workspace →
MBIO offering FAQ

When did MBIO last execute an offering?

Per SEC filings, MUSTANG BIO, INC.'s most recent priced offering document is a 424B5 filed 2025-09-05. Note a 424B takedown can price shares or notes (debt) — the linked document says which.

When did MBIO last announce or register an offering?

The most recent registration is a S-1/A filed 2025-02-05. 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.