SECURITIESFORM AND EXCHANGE COMMISSION8-K

EmergingItem growth2.02 company ☒Results of Operations and Financial Condition.

OnItem April 1, 2025, Boundless Bio, Inc9.01 (theFinancial Company)Statements enteredand into an Open Market Sale AgreementSM (the Sales Agreement) with Jefferies LLC (the Agent), under which the Company may, from time to time, sell shares of the Company’s common stock in “at the market offerings” through or to the Agent, as sales agent or principalExhibits. Pursuant to the Sales Agreement prospectus, the Company may sell shares of common stock having an aggregate offering price of up to $14.5 million. Sales of the shares of common stock, if any, will be made at prevailing market prices at the time of sale, or as otherwise agreed with the Agent. The Agent will receive a commission from the Company of up to 3.0% of the gross proceeds of any shares of common stock sold under the Sales Agreement.

UNITED ~~STATES~~STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549

~~WASHINGTON,~~CURRENT ~~D.C. 20549~~REPORT

~~FORM~~Pursuant ~~8-K~~to Section 13 or 15(d) of the Securities Exchange Act of 1934

~~CURRENT~~Date ~~REPORT~~of Report (Date of earliest event reported): May 09, 2025

~~Pursuant~~Boundless toBio, ~~Section 13 or 15(d)~~Inc.

(Exact Name of ~~the~~Registrant ~~Securities~~as ~~Exchange~~Specified ~~Act~~in ofIts ~~1934~~Charter)

Date of Report (Date of earliest event reported): April 1, 2025


Delaware	001-41989	83-0751369
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)

10955 Alexandria Way, Suite 100,
San Diego, California		92121
(Address of Principal Executive Offices)		(Zip Code)

~~Boundless~~Registrant’s ~~Bio~~Telephone Number, ~~Inc.~~Including Area Code: (858) 766-9912

~~(Exact Name of Registrant as Specified in Its Charter)~~N/A

Delaware	001-41989	83-0751369
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)
10955 Alexandra Way, Suite 100,
San Diego, California		92121
(Address of Principal Executive Offices)		(Zip Code)

(Former Name or Former Address, if Changed Since Last Report)

~~Registrant’s~~Check ~~Telephone~~the ~~Number,~~appropriate ~~Including~~box ~~Area~~below ~~Code:~~if ~~(858)~~the ~~766~~Form 8-~~9912~~K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

~~(Former~~☐Written ~~Name~~communications orpursuant ~~Former~~to ~~Address,~~Rule if425 ~~Changed~~under ~~Since~~the ~~Last~~Securities ~~Report~~Act (17 CFR 230.425)

~~Check~~☐Soliciting ~~the~~material ~~appropriate~~pursuant ~~box~~to ~~below~~Rule ~~if the Form 8~~14a-K12 ~~filing~~under ~~is intended to simultaneously satisfy~~ the ~~filing~~Exchange ~~obligation~~Act of(17 ~~the~~CFR ~~registrant under any of the following provisions:~~240.14a-12)

☐Pre-commencement ~~Written~~ communications pursuant to Rule ~~425~~14d-2(b) under the ~~Securities~~Exchange Act (17 CFR ~~230~~240.~~425~~14d-2(b))

☐Pre-commencement ~~Soliciting~~communications ~~material~~ pursuant to Rule ~~14a~~13e-124(c) under the Exchange Act (17 CFR 240.~~14a~~13e-124(c))

☐Securities ~~Pre-commencement~~registered ~~communications~~ pursuant to ~~Rule~~Section ~~14d-2~~12(b) ~~under~~of 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))


Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, par value $0.0001 per share	BOLD	Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities ~~registered~~Act ~~pursuant~~of to1933 ~~Section 12~~(b§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act: of 1934 (§ 240.12b-2 of this chapter).

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock, par value $0.0001 per share		BOLD		Nasdaq Global Select Market

Emerging growth company ☒

~~Indicate~~If an emerging growth company, indicate by check mark ~~whether~~if the registrant ishas anelected ~~emerging~~not ~~growth~~to ~~company~~use asthe ~~defined~~extended intransition ~~Rule~~period ~~405~~for ofcomplying ~~the~~with ~~Securities~~any ~~Act~~new ofor ~~1933~~revised ~~(§ 230.405~~financial ofaccounting ~~this~~standards ~~chapter)~~provided orpursuant ~~Rule~~to ~~12b-2~~Section 13(a) of the ~~Securities~~ Exchange Act ~~of 1934 (§ 240~~.~~12b-2~~ ~~of this chapter).~~☐

IfOn anMay ~~emerging~~9, ~~growth~~2025, ~~company~~Boundless Bio, ~~indicate~~Inc. by(the ~~check~~Company) ~~mark~~issued ifa ~~the~~press ~~registrant~~release ~~has~~announcing ~~elected~~its ~~not~~financial toresults ~~use~~for the ~~extended~~quarter ~~transition~~ended ~~period~~March ~~for~~31, ~~complying~~2025. ~~with~~A ~~any~~copy ~~new~~of orthe ~~revised~~press ~~financial~~release ~~accounting~~is ~~standards~~attached ~~provided~~hereto ~~pursuant~~as toExhibit ~~Section 13(a)~~99.1 ofand ~~the~~is ~~Exchange~~incorporated ~~Act~~herein by reference. ☐

~~Item~~In 1accordance with General Instruction B.012 ~~Entry~~of ~~into~~Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the Exchange Act), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, whether made before or after the date hereof and regardless of any general incorporation by reference language in any such filing, unless the Company specifically states in such filing that such information, or a ~~Material~~portion ~~Definitive~~thereof, ~~Agreement~~is to be considered “filed” rather than furnished or incorporated by reference therein.

BOUNDLESS BIO, INC.

Date: April 1, 2025

/s/ Jessica Oien

Jessica Oien

Chief Legal Officer and Corporate Secretary

~~The~~(d) ~~Company is not obligated to sell, and the Agent is not obligated to buy or sell, any shares of common stock under the Sales Agreement~~Exhibits. No assurance can be given that the Company will sell any shares of common stock under the Sales Agreement, or, if it does, as to the price or amount of shares of common stock that it sells or the dates when such sales will take place.

In the Sales Agreement, the Company agreed to indemnify the Agent against certain liabilities, including under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, or to contribute to payments that the Agent may be required to make because of such liabilities. The Company and the Agent may each terminate the Sales Agreement at any time upon specified prior written notice.


Exhibit Number		Description
99.1		Press Release Issued on May 9, 2025
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

The shares of common stock will be issued pursuant to the Company’s shelf registration statement on Form S-3, including the Sales Agreement prospectus contained therein, filed with the Securities and Exchange Commission (the SEC) on April 1, 2025 (the Registration Statement), once the Registration Statement is declared effective by the SEC. A copy of the Sales Agreement is attached as Exhibit 1.1 hereto and is incorporated herein by reference. The foregoing description of the Sales Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Sales Agreement. SIGNATURES

APursuant ~~copy~~to of the ~~opinion~~requirements of ~~Latham &~~the ~~Watkins~~Securities ~~LLP~~Exchange ~~relating~~Act toof 1934, the ~~validity~~registrant ofhas ~~the~~duly ~~shares~~caused ofthis ~~common~~report ~~stock~~to ~~that~~be ~~may~~signed beon ~~sold~~its ~~pursuant~~behalf toby the ~~Sales~~undersigned ~~Agreement~~hereunto isduly ~~filed herewith as Exhibit 5~~authorized.1.

Item 9.01 Financial Statements and Exhibits.


			BOUNDLESS BIO, INC.

Date:	May 9, 2025	By:	/s/ Jessica Oien
			Name: Jessica Oien Title: Chief Legal Officer and Corporate Secretary

(d) Exhibits.

Exhibit Number		Description
1.1		Open Market Sale AgreementSM by and between the Registrant and Jefferies LLC, dated April 1, 2025 (incorporated by reference to Exhibit 1.2 to the Company’s Registration Statement on Form S-3 filed with the Securities and Exchange Commission on April 1, 2025)
5.1		Opinion of Latham & Watkins LLP (incorporated by reference to Exhibit 5.2 to the Company’s Registration Statement on Form S-3 filed with the Securities and Exchange Commission on April 1, 2025)
23.1		Consent of Latham & Watkins LLP (included in Exhibit 5.1)
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.

Filing Compare · Boundless Bio, Inc.