Highbridge Files 13G for 7.1% of Plus Therapeutics

Plus Therapeutics: Highbridge reports beneficial ownership of warrants exercisable into common stock.

Rhea-AI Filing Summary

Plus Therapeutics: Highbridge reports beneficial ownership of warrants exercisable into common stock. The Schedule 13G states 13,157,894 shares of Common Stock are attributable to Highbridge Capital Management, LLC, representing 7.1% of the class based on 171,550,698 shares outstanding as of March 18, 2026. The shares are described as issuable upon exercise of warrants; the filing attributes voting and dispositive powers to the reporting person and names Highbridge Tactical Credit Master Fund, L.P. as a fund holding more than 5%.

Insights

Institutional Ownership Analyst

Highbridge reports a 7.1% position in Plus Therapeutics via warrant holdings.

The filing lists 13,157,894 shares attributable to Highbridge, calculated on an outstanding share base of 171,550,698 shares as of March 18, 2026. The position is described as issuable upon exercise of warrants, so actual common shares depend on future exercises.

Cash‑flow treatment and exercise timing are not specified in the excerpt; subsequent disclosures or transactions will determine whether these warrants convert to outstanding common shares and affect ownership percentages.

Capital Markets Counsel

This is an ownership disclosure under Schedule 13G, not a securities offering or sale.

The statement identifies the Reporting Person as the investment adviser to Highbridge Funds and notes voting and dispositive powers over the warrant‑derived shares. It also specifies a fund with rights to proceeds exceeding 5%.

Qualifying language clarifies the shares are "issuable upon exercise of warrants"; any change in reported ownership depends on future exercises and should be tracked in subsequent filings.

Key Figures

Beneficial shares attributable: 13,157,894 shares Percent of class: 7.1% Shares outstanding used: 171,550,698 shares +1 more

4 metrics

Beneficial shares attributable 13,157,894 shares issuable upon exercise of warrants

Percent of class 7.1% calculated on 171,550,698 shares outstanding as of <date>March 18, 2026</date>

Shares outstanding used 171,550,698 shares as of <date>March 18, 2026</date> (source: issuer proxy statement)

Reporting date / signature <date>May 15, 2026</date> Schedule 13G signature date

Key Terms

issuable upon exercise of warrants, Schedule 13G, beneficial ownership, sole dispositive power

4 terms

issuable upon exercise of warrants financial

"Reflects shares of Common Stock issuable upon exercise of warrants."

Schedule 13G regulatory

"This statement is filed by Highbridge Capital Management, LLC"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

beneficial ownership financial

"Amount beneficially owned: The information required by Item 4(a) is set forth"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

sole dispositive power regulatory

"Sole Dispositive Power 13,157,894.00"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What stake does Highbridge report in Plus Therapeutics (PSTV)?

Highbridge reports beneficial ownership of 13,157,894 shares, representing 7.1% of the class. This percentage is calculated using 171,550,698 shares outstanding as of March 18, 2026 and assumes exercise of warrants held by Highbridge Funds.

Are the reported shares already outstanding common stock for PSTV?

No. The filing states the shares are issuable upon exercise of warrants, not currently outstanding common stock. Actual conversion into outstanding shares depends on future warrant exercises and related disclosures.

Which Highbridge entity holds more than 5% of PSTV?

Highbridge Tactical Credit Master Fund, L.P. is identified as a Highbridge Fund that has the right to receive dividends or proceeds from sale exceeding 5% of the outstanding common stock.

Does the Schedule 13G indicate voting or disposition authority for Highbridge?

Yes. The cover rows cited show Highbridge has sole voting power and sole dispositive power over the 13,157,894 shares attributable to it, as reported on the filing's cover page.

What is the date used to calculate the ownership percentage for PSTV?

The percentage is calculated using the issuer's share count of 171,550,698 shares outstanding as of March 18, 2026, cited from the issuer's Definitive Proxy Statement filed March 31, 2026.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 05/15/2026 - 06:45 AM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

PLUS THERAPEUTICS, INC.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

72941H806

(CUSIP Number)

03/31/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 72941H806

1

Names of Reporting Persons

Highbridge Capital Management, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 13,157,894.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 13,157,894.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

13,157,894.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

7.1 %

12

Type of Reporting Person (See Instructions)

IA, OO

Comment for Type of Reporting Person: Reflects shares of Common Stock (as defined in Item 2(a)) issuable upon exercise of warrants.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: PLUS THERAPEUTICS, INC.
(b)	Address of issuer's principal executive offices: 6420 Levit Green Boulevard, Suite 310, Houston, Texas 77021
Item 2.
(a)	Name of person filing: This statement is filed by Highbridge Capital Management, LLC ("Highbridge" or the "Reporting Person"), a Delaware limited liability company and the investment adviser to certain funds and accounts (the "Highbridge Funds"), with respect to the common stock, par value $0.001 per share ("Common Stock") of Plus Therapeutics, Inc., a Delaware corporation (the "Issuer"), issuable upon exercise of warrants directly held by the Highbridge Funds; The filing of this statement should not be construed as an admission that any of the foregoing persons or the Reporting Person is, for the purposes of Section 13 of the Securities Exchange Act of 1934, the beneficial owner of the securities reported herein.
(b)	Address or principal business office or, if none, residence: The address of the business office of the Reporting Person is 390 Madison Avenue, 28th Floor, New York, NY 10017.
(c)	Citizenship: Highbridge is a Delaware limited liability company.
(d)	Title of class of securities: Common Stock, par value $0.001 per share
(e)	CUSIP Number(s): 72941H806
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: The information required by Item 4(a) is set forth in Row 9 of the cover page for the Reporting Person and is incorporated herein by reference. The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 171,550,698 shares of Common Stock outstanding as of March 18, 2026, as reported in the Issuer's Definitive Proxy Statement on Schedule 14A filed with the Securities and Exchange Commission on March 31, 2026, and assumes the exercise of the warrants held by the Highbridge Funds.
(b)	Percent of class: 7.1%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for the Reporting Person and is incorporated herein by reference.
	(ii) Shared power to vote or to direct the vote: The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for the Reporting Person and is incorporated herein by reference.
	(iii) Sole power to dispose or to direct the disposition of: The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for the Reporting Person and is incorporated herein by reference.
	(iv) Shared power to dispose or to direct the disposition of: The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for the Reporting Person and is incorporated herein by reference.
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. See Item 2(a). The Highbridge Funds have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock reported herein. Highbridge Tactical Credit Master Fund, L.P., a Highbridge Fund, has the right to receive or the power to direct the receipt of dividends or the proceeds from the sale of more than 5% of the outstanding Common Stock.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Highbridge Capital Management, LLC

Signature:	/s/ Kirk Rule
Name/Title:	Kirk Rule, Executive Director
Date:	05/15/2026