Rallybio Corp Schedule 13G reports that Laurion Capital Management and two co-managing members beneficially own 302,756 shares of Rallybio Common Stock, representing 5.72% of the class as of 03/31/2026. The filing states the shares are held by Laurion Funds, with shared voting and dispositive power among Laurion Capital, Benjamin A. Smith, and Janaka S. Maduraperuma. The statement clarifies that Laurion Capital Master Fund Ltd. holds more than 5% of the class and identifies the reporting persons and their business address.
Positive
None.
Negative
None.
Insights
Passive 13G filing: an institutional holder reports >5% ownership.
This Schedule 13G indicates institutional disclosure rather than activist intent; Laurion Funds report beneficial ownership of 302,756 shares (5.72%) as of 03/31/2026. The disclosure shows shared voting and dispositive power among the adviser and two co-managers.
Shareholder actions will depend on Laurion's strategy; subsequent filings (e.g., a Schedule 13D or Form 4) would indicate active engagement or transactional activity. Timing for any change is not stated in the excerpt.
Key Figures
Shares beneficially owned:302,756 sharesPercent of class:5.72%Report date:03/31/2026+2 more
5 metrics
Shares beneficially owned302,756 sharesAmount beneficially owned as reported in Item 4(a)
Percent of class5.72%Percent of common stock as reported in Item 4(b)
Report date03/31/2026Position date shown at top of the filing
Signature date04/29/2026Dates on signatures of reporting persons and counsel
CUSIP75120L209CUSIP for Rallybio Common Stock listed in Item 2(d)/(e)
"This statement is filed by: (i) Laurion Capital Management LP"
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 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.
shared dispositive powerregulatory
"Shared Dispositive Power 302,756.00"
investment adviserfinancial
"Laurion Capital, a Delaware limited partnership, and the investment adviser to certain funds"
An investment adviser is a person or firm that professionally manages money and gives recommendations about buying, selling, or holding investments. Like a financial coach or guide, they have a legal duty to act in a client's best financial interest, so their advice, fees and potential conflicts can directly affect returns and risk — making their role important for investors who want informed, accountable help with portfolios.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
Rallybio Corp
(Name of Issuer)
Common Stock, par value $0.0001 per share
(Title of Class of Securities)
75120L209
(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):
75120L209
1
Names of Reporting Persons
Laurion Capital Management LP
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
0.00
6
Shared Voting Power
302,756.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
302,756.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
302,756.00
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)
5.72 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP Number(s):
75120L209
1
Names of Reporting Persons
Benjamin Alexander Smith
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
0.00
6
Shared Voting Power
302,756.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
302,756.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
302,756.00
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)
5.72 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
CUSIP Number(s):
75120L209
1
Names of Reporting Persons
Janaka Sheehan Maduraperuma
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 KINGDOM
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
302,756.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
302,756.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
302,756.00
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)
5.72 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Rallybio Corp
(b)
Address of issuer's principal executive offices:
234 CHURCH STREET, SUITE 1020, NEW HAVEN, CONNECTICUT
06510
Item 2.
(a)
Name of person filing:
This statement is filed by:
(i) Laurion Capital Management LP ("Laurion Capital"), a Delaware limited partnership, and the investment adviser to certain funds and accounts (the "Laurion Funds"), with respect to the shares of Common Stock (as defined in Item 2(d) below) directly held by the Laurion Funds;
(ii) Mr. Benjamin Alexander Smith ("Mr. Smith"), the co-managing member of Laurion Capital GP LLC, the general partner of Laurion Capital, with respect to the shares of Common Stock directly held by the Laurion Funds.
(iii) Mr. Janaka Sheehan Maduraperuma ("Mr. Maduraperuma"), the co-managing member of Laurion Capital GP LLC, the general partner of Laurion Capital, with respect to the shares of Common Stock directly held by the Laurion Funds.
The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons."
The filing of this statement should not be construed as an admission that any of the forgoing persons or any Reporting Person is, for the purposes of Section 13 of the Act, the beneficial owner of the shares of Common Stock reported herein.
(b)
Address or principal business office or, if none, residence:
The address of the business office of each of the Reporting Persons is 360 Madison Avenue, Suite 1900, New York, NY 10017.
(c)
Citizenship:
Laurion Capital is a Delaware limited partnership. Mr. Smith is a citizen of the United States. Mr. Maduraperuma is a citizen of the United Kingdom.
(d)
Title of class of securities:
Common Stock, par value $0.0001 per share
(e)
CUSIP Number(s):
75120L209
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:
302,756
(b)
Percent of class:
5.72 %
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
Laurion Capital Management LP - 0
Benjamin Alexander Smith - 0
Janaka Sheehan Maduraperuma - 0
(ii) Shared power to vote or to direct the vote:
Laurion Capital Management LP - 302,756
Benjamin Alexander Smith - 302,756
Janaka Sheehan Maduraperuma - 302,756
(iii) Sole power to dispose or to direct the disposition of:
Laurion Capital Management LP - 0
Benjamin Alexander Smith - 0
Janaka Sheehan Maduraperuma - 0
(iv) Shared power to dispose or to direct the disposition of:
Laurion Capital Management LP - 302,756
Benjamin Alexander Smith - 302,756
Janaka Sheehan Maduraperuma - 302,756
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. The Laurion 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. Laurion Capital Master Fund Ltd., a Laurion 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 shares of 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.
What stake does Laurion Capital report in Rallybio (RLYB)?
Laurion reports beneficial ownership of 302,756 shares, equal to 5.72% of Rallybio's common stock as of 03/31/2026. The filing attributes voting and dispositive power as shared among Laurion Capital and two co-managing members.
Who are the named reporting persons on the Schedule 13G for RLYB?
The filing names Laurion Capital Management LP, Benjamin Alexander Smith, and Janaka Sheehan Maduraperuma as reporting persons. Their business address is listed as 360 Madison Avenue, Suite 1900, New York, NY.
Does the Schedule 13G indicate Laurion is an activist owner?
No. This Schedule 13G is a passive/institutional disclosure showing >5% ownership. The filing does not state activist intentions or requests for changes; it lists shared voting/dispositive power without indicating engagement plans.
What date does this ownership disclosure cover for Rallybio?
The ownership amount is reported as of 03/31/2026, and the signatures on the statement are dated 04/29/2026. The share count and percentage are tied to the March 31, 2026 position.
