Filed Pursuant to Rule 424(b)(3)
Registration No. 333-291984
Prospectus Supplement No. 6
(To Prospectus dated December 5, 2025, as supplemented by
Prospectus Supplement No. 1 dated December 19, 2025
Prospectus Supplement No. 2 dated January 8, 2026
Prospectus Supplement No. 3 dated February 3, 2026
Prospectus Supplement No. 4 dated February 4, 2026
Prospectus Supplement No. 5 dated February 20, 2026)

CERO THERAPEUTICS HOLDINGS, INC.
729,596,950 Shares of Common Stock
This prospectus supplement no. 6 (this “Prospectus
Supplement”) amends and supplements the prospectus dated December 5, 2025 (as may be supplemented or amended from time to time,
the “Prospectus”), which forms part of our Registration Statement on Form S-1 (Registration Statement No. 333-291984). This
Prospectus Supplement is being filed to update and supplement the information included or incorporated by reference in the Prospectus
with the information contained in the attached Current Report on Form 8-K, filed with the Securities and Exchange Commission (the “Securities
and Exchange Commission”) on March 11, 2026 (the “Form 8-K”). Accordingly, we have attached the Form 8-K to this Prospectus
Supplement.
This Prospectus Supplement updates and supplements
the information in the Prospectus and is not complete without, and may not be delivered or utilized except in combination with, the Prospectus,
including any amendments or supplements thereto. This Prospectus Supplement should be read in conjunction with the Prospectus, and if
there is any inconsistency between the information in the Prospectus and this Prospectus Supplement, you should rely on this Prospectus
Supplement.
Our common stock is traded on OTCQB under the
symbol “CERO” and our public warrants is traded on OTCID under the symbol “CEROW,” respectively. On March 10,
2026, the last quoted bid price of our common stock as reported on OTCQB was $0.0341 per share and the last quoted bid price of our public
warrants as reported on OTCID was $0.0052 per warrant.
We are an “emerging growth company”
under applicable federal securities laws and will be subject to reduced public company reporting requirements.
Investing in our securities involves a high
degree of risk. Before buying any securities, you should carefully read the discussion of the risks of investing in our securities in
“Risk Factors” beginning on page 8 of the Prospectus.
Neither the Securities and Exchange Commission
nor any state securities commission has approved or disapproved of the securities to be issued under the Prospectus or determined if the
Prospectus is truthful or complete. Any representation to the contrary is a criminal offense.
The date of this Prospectus Supplement is March
11, 2026.
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant to Section 13 or Section 15(d)
of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported):
March 6, 2026
CERO THERAPEUTICS HOLDINGS, INC.
(Exact name of registrant as specified in its
charter)
| Delaware |
|
001-40877 |
|
81-4182129 |
(State or other jurisdiction of
incorporation or organization) |
|
(Commission File Number) |
|
(I.R.S. Employer
Identification Number) |
201 Haskins Way, Suite 230,
South San Francisco, CA |
|
94080 |
| (Address of principal executive offices) |
|
(Zip Code) |
(650) 407-2376
Registrant’s telephone number, including
area code
Not applicable
(Former name or former address, if changed since
last report)
Check the appropriate box below if the Form 8-K
filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:
| ☐ | Written communications pursuant to Rule 425 under the Securities
Act (17 CFR 230.425) |
| ☐ | Soliciting material pursuant to Rule 14a-12 under the Exchange
Act (17 CFR 240.14a-12) |
| ☐ | Pre-commencement communications pursuant to Rule 14d-2(b)
under the Exchange Act (17 CFR 240.14d-2(b)) |
| ☐ | Pre-commencement communications pursuant to Rule 13e-4(c)
under the Exchange Act (17 CFR 240.13e-4(c)) |
Securities registered pursuant to Section 12(b)
of the Act:
| Title of each class |
|
Trading Symbol(s) |
|
Name of each exchange on which registered |
| Common Stock, par value $0.0001 per share |
|
CERO |
|
None |
| Warrants, each warrant exercisable for one two-thousandths of a share of Common Stock |
|
CEROW |
|
None |
Indicate by check mark whether the registrant
is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 or Rule 12b-2 of the Securities Exchange Act of 1934.
Emerging growth company ☒
If an emerging growth company, indicate by check
mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting
standards provided pursuant to Section 13(a) of the Exchange Act. ☐
Item 1.01 Entry into a Material Definitive
Agreement.
On March 6, 2026, CERo Therapeutics Holdings,
Inc., a Delaware corporation (the “Company”) issued and sold a convertible promissory note for a purchase price of $750,000,
having a principal face value of $937,500 (the “Note”) to Keystone Capital Partners, LLC (“Lender”). Pursuant
to the Note, the Company may borrow, from time to time thereunder, up to a maximum aggregate amount not to exceed a sum of $1,000,000.
The Note bears interest at a rate of 10% per annum, matures on August 6, 2027, and is convertible into shares of the Company’s common
stock, par value $0.0001 per share (the “Common Stock”). At any time after the issuance of the Note, the Lender, at its option,
is entitled to convert all or any lesser portion of the outstanding principal amount and accrued but unpaid interest into Common Stock
at a conversion price equal to the lesser of (i) $0.05 and (ii) 80% of the average of the 5 (five) lowest intraday trading prices during
the 20 (twenty) days prior to the day that the Lender requests conversion, unless otherwise modified by mutual agreement between the parties,
subject to certain adjustments and limitations, including a beneficial ownership limitation of 4.99%.
Pursuant to the terms of the Note, the Company
shall prepare and file with the U.S. Securities and Exchange Commission (the “SEC”), a registration statement on Form S-1
or S-3, covering the resale of all of the shares of Common Stock issuable upon the conversion of the Note.
The issuance of the Note was made in reliance
upon the exemption from registration provided by Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”),
and Rule 506(b) promulgated thereunder. The Note and the shares of Common Stock issuable upon conversion thereof have not been registered
under the Securities Act and may not be offered or sold in the United States absent registration or an applicable exemption from registration
requirements.
The foregoing description of the Note is qualified
in its entirety by reference to the full text of such document, a copy of which was previously filed as Exhibit 4.1 to the Company’s
Current Report on Form 8-K filed on February 13, 2026 and is incorporated herein by reference.
Item 2.03 Creation of a Direct Financial Obligation
or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.
The information set forth under Item 1.01 of this
Current Report on Form 8-K is incorporated by reference into this Item 2.03.
Item 3.02 Unregistered Sales of Equity Securities.
The information set forth under Item 1.01 of this
Current Report on Form 8-K is incorporated by reference into this Item 3.02. The issuance of the Note was made in reliance on the exemption
provided by Section 4(a)(2) of the Securities Act, for the offer and sale of securities not involving a public offering. The Company’s
reliance upon Section 4(a)(2) of the Securities Act in issuing the Note was based upon the following factors: (a) the issuance of the
Note was an isolated private transaction by us which did not involve a public offering; (b) the Lender is an accredited investor;
(c) the Company did not engage in general solicitation or advertising in connection with the issuance; and (d) the Lender represented
that, among other things, it was acquiring the securities for investment purposes only and not with a view to distribution, it has received
information about the Company necessary to make an informed investment decision, and the Lender is capable of evaluating the merits and
risks of its investment. Any shares of Common Stock issuable upon conversion of the Note will be issued in reliance on the exemption from
registration provided by Section 3(a)(9) or Section 4(a)(2) of the Securities Act.
Item 9.01 Financial Statements and Exhibits.
(d) Exhibits
| Exhibit No. |
|
Description |
| 4.1 |
|
Form of Note (incorporated by reference to Exhibit 4.1 of the Company’s Current Report on Form 8-K (File No. 001-40877) filed on February 13, 2026). |
| 104 |
|
Cover Page Interactive Data File (embedded within the Inline XBRL document). |
SIGNATURES
Pursuant to the requirements of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
| Dated: March 11, 2026 |
CERO THERAPEUTICS HOLDINGS, INC. |
| |
|
| |
By: |
/s/ Chris Ehrlich |
| |
Name: |
Chris Ehrlich |
| |
Title: |
Chief Executive Officer |