SeaStar Medical Holding Corporation ownership disclosure: Ayrton Capital LLC, Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B, and Waqas Khatri each report beneficial ownership of 278,436 shares of common stock issuable upon exercise of warrants. This holding represents 6.52% of the class based on 3,993,719 shares outstanding as of March 24, 2026. The issuable shares are subject to a 9.99% beneficial ownership blocker. The reported holdings are stated as of March 31, 2026.
Positive
None.
Negative
None.
Insights
Large warrant position equal to 6.52% of the class is disclosed.
The filing shows 278,436 shares issuable upon exercise of warrants held by the reporting persons, representing 6.52% of common stock on the stated basis. The disclosure cites 3/24/2026 outstanding shares as the denominator.
Execution depends on the 9.99% beneficial ownership blocker and holder decisions; timing and cash‑flow treatment for any exercise are not stated in the excerpt.
Ownership is routed through an investment manager and a fund structure.
The excerpt identifies the Fund as the direct holder and Ayrton Capital LLC as its investment manager, with Waqas Khatri as managing member. Voting and dispositive power are reported as sole for the listed 278,436 shares.
Beneficial ownership attribution follows the ownership chain; footnote-style disclosures anchor control but do not describe any planned transactions.
Key Figures
Shares issuable on exercise:278,436 sharesPercent of class:6.52%Shares outstanding (denominator):3,993,719 shares+1 more
4 metrics
Shares issuable on exercise278,436 sharesWarrants held by the reporting persons
Percent of class6.52%Based on 3,993,719 shares outstanding as of March 24, 2026
Shares outstanding (denominator)3,993,719 sharesOutstanding common stock as of March 24, 2026 (source: issuer 10-K)
Beneficial ownership blocker9.99%Limit applied to issuable shares from the Warrants
"Represents 278,436 shares of Common Stock issuable on the exercise of certain warrants"
Warrants are special documents that give you the right to buy a company's stock at a set price before a certain date. They are often used as a way for companies to attract investors or raise money, and their value can increase if the company's stock price goes up.
Beneficial ownership blockerregulatory
"The issuable shares of Common Stock related to the exercise of the Warrants are subject to a 9.99% beneficial ownership blocker"
A beneficial ownership blocker is a legal or structural device that prevents a shareholder from being treated as the ultimate owner of enough shares to trigger control, reporting, or voting thresholds. Think of it like a speed bump that stops an investor from reaching a stake size that would force corporate disclosure or change control rights. Investors care because it affects who controls the company, how shares vote, regulatory filings, takeover risk and therefore potential value or liquidity of their holdings.
Beneficially ownedregulatory
"Amount beneficially owned: Ayrton Capital LLC: 278,436"
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
What stake does Ayrton Capital report in SeaStar Medical (ICU)?
Ayrton Capital reports beneficial ownership of 278,436 shares issuable upon exercise of warrants, representing 6.52% of the class using the issuer's March 24, 2026 outstanding share figure. Holdings are reported as of March 31, 2026.
Are the reported SeaStar shares currently outstanding or issuable (ICU)?
The 278,436 shares are described as issuable on exercise of warrants, not presently outstanding common stock. The filing ties percentages to the issuer's outstanding share count of 3,993,719 as of March 24, 2026.
What is the "beneficial ownership blocker" mentioned in the filing for ICU?
The filing states the issuable shares from the warrants are subject to a 9.99% beneficial ownership blocker, limiting exercises that would otherwise increase reported ownership above that percentage threshold.
Who holds voting and dispositive power over the SeaStar warrants (ICU)?
The filing reports that Ayrton Capital LLC, the Fund, and Waqas Khatri each have sole voting and sole dispositive power over the 278,436 shares issuable upon exercise of the warrants, per the Schedule 13G disclosure.
What denominator did the filing use to calculate the 6.52% for ICU?
The percentage is based on 3,993,719 shares of common stock outstanding as of March 24, 2026, combined with the 278,436 shares issuable on exercise of the warrants held by the reporting persons.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
SeaStar Medical Holding Corporation
(Name of Issuer)
Common stock, par value $0.0001 per share
(Title of Class of Securities)
81256L203
(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):
81256L203
1
Names of Reporting Persons
Ayrton Capital 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
278,436.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
278,436.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
278,436.00
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)
6.52 %
12
Type of Reporting Person (See Instructions)
IA
SCHEDULE 13G
CUSIP Number(s):
81256L203
1
Names of Reporting Persons
Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B
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
CAYMAN ISLANDS
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
278,436.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
278,436.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
278,436.00
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)
6.52 %
12
Type of Reporting Person (See Instructions)
CO
SCHEDULE 13G
CUSIP Number(s):
81256L203
1
Names of Reporting Persons
Waqas Khatri
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
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
278,436.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
278,436.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
278,436.00
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)
6.52 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
SeaStar Medical Holding Corporation
(b)
Address of issuer's principal executive offices:
3513 Brighton Blvd, Suite 410, Denver, CO 80216
Item 2.
(a)
Name of person filing:
(i) Ayrton Capital LLC; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B; and (iii) Waqas Khatri
(b)
Address or principal business office or, if none, residence:
(i) Ayrton Capital LLC, 55 Post Rd West, 2nd Floor Westport, CT 06880; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B, Suite #7 Grand Pavilion Commercial Centre, 802 West Bay Road, Grand Cayman, P.O. Box 10250, Cayman Islands; and (iii) Waqas Khatri 55 Post Rd West, 2nd Floor Westport, CT 06880
(c)
Citizenship:
(i) Ayrton Capital LLC: United States; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: Cayman Islands; and (iii) Waqas Khatri: United States
(d)
Title of class of securities:
Common stock, par value $0.0001 per share
(e)
CUSIP Number(s):
81256L203
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:
Ayrton Capital LLC: 278,436; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 278,436; and (iii) Waqas Khatri: 278,436. Represents 278,436 shares of Common Stock issuable on the exercise of certain warrants (the "Warrants") held by the Reporting Persons. The issuable shares of Common Stock related to the exercise of the Warrants are subject to a 9.99% beneficial ownership blocker. The shares reported herein represent Common Stock of SeaStar Medical Holding Corporation (the "Issuer") held by Alto Opportunity Master Fund, SPC- Segregated Master Portfolio B, a Cayman Islands exempted company (the "Fund"). The Fund is a private investment vehicle for which Ayrton Capital LLC, a Delaware limited liability company (the "Investment Manager"), serves as the investment manager. Waqas Khatri serves as the managing member of the Investment Manager (all of the foregoing, collectively, the "Reporting Persons").
(b)
Percent of class:
The percentages below are based on (i) 3,993,719 shares of Common Stock of the Issuer that were outstanding as of March 24, 2026; and (ii) 278,436 shares of Common Stock issuable on the exercise of the Warrants held by the Reporting Persons. The amount of shares outstanding was based upon a statement in the Issuer's 10-K filing on March 25, 2026. For the sake of clarity, the holdings of the Reporting Persons reported herein are as of March 31, 2026. (i) Ayrton Capital LLC: 6.52%; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 6.52%; and (iii) Waqas Khatri: 6.52%.
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
(i) Ayrton Capital LLC: 278,436; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 278,436; and (iii) Waqas Khatri: 278,436
(ii) Shared power to vote or to direct the vote:
(i) Ayrton Capital LLC: 0; (ii) Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 0; and (iii) Waqas Khatri: 0
(iii) Sole power to dispose or to direct the disposition of:
Ownership of more than 5 Percent on Behalf of Another Person.
Not Applicable
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.
Ayrton Capital LLC
Signature:
/s/ Waqas Khatri
Name/Title:
Waqas Khatri / Managing Member
Date:
05/11/2026
Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B
