STOCK TITAN

ADAR1-managed funds boost Rallybio (RLYB) stake with open-market share buys

Filing Impact
(Moderate)
Filing Sentiment
(Positive)
Form Type
4

Rhea-AI Filing Summary

Rallybio Corp disclosed that private investment funds and separately managed accounts managed by ADAR1 Capital Management, LLC made open-market purchases of Rallybio common stock. Across May 18–19, 2026, these ADAR1-managed vehicles bought a total of 16,209 shares at weighted average prices near $14 per share.

Following these transactions, the ADAR1-managed funds and accounts indirectly held 926,352 Rallybio shares. ADAR1 Capital Management and Daniel Schneeberger, each a 10% owner, may be deemed indirect beneficial owners but expressly disclaim beneficial ownership beyond any pecuniary interest.

Positive

  • None.

Negative

  • None.
Insider ADAR1 Capital Management, LLC, Schneeberger Daniel
Role null | null
Bought 16,209 shs ($227K)
Type Security Shares Price Value
Purchase Common Stock 10,000 $13.9822 $140K
Purchase Common Stock 200 $13.80 $3K
Purchase Common Stock 6,009 $13.9759 $84K
Holdings After Transaction: Common Stock — 926,152 shares (Indirect, See Footnote)
Footnotes (1)
  1. The reported price is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $13.9100 to $14.0000, inclusive. Each Reporting Person undertakes to provide Rallybio Corp, any security holder of Rallybio Corp or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. The reported price is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $13.9350 to $14.0000, inclusive. Each Reporting Person undertakes to provide to Rallybio Corp, any security holder of Rallybio Corp or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. The reported securities are owned directly by private investment funds managed by ADAR1 Capital Management, LLC and separately managed accounts of ADAR1 Capital Management, LLC, and may be deemed to be indirectly beneficially owned by (i) ADAR1 Capital Management, LLC and (ii) Daniel Schneeberger, the sole manager of ADAR1 Capital Management, LLC. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.
Total shares purchased 16,209 shares Open-market buys on May 18–19, 2026
Purchase price (trade 1) $13.8000 per share 200-share open-market purchase on May 19, 2026
Purchase price (trade 2) $13.9822 per share 10,000-share open-market purchase on May 19, 2026
Purchase price (trade 3) $13.9759 per share 6,009-share open-market purchase on May 18, 2026
Post-transaction holdings 926,352 shares Indirect holdings by ADAR1-managed vehicles after May 19, 2026
Price range (F1 footnote) $13.9100–$14.0000 Weighted average purchase range for one set of trades
Price range (F2 footnote) $13.9350–$14.0000 Weighted average purchase range for another trade set
open-market purchase financial
"transaction_action: open-market purchase"
An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.
weighted average price financial
"The reported price is a weighted average price."
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
indirectly beneficially owned financial
"may be deemed to be indirectly beneficially owned by (i) ADAR1 Capital Management, LLC"
separately managed accounts financial
"private investment funds managed by ADAR1 Capital Management, LLC and separately managed accounts"
A separately managed account is an investment portfolio owned by a single investor but professionally managed to that investor’s specific goals and preferences, rather than pooled with other clients’ money. It matters to investors because it offers greater customization, tax control and transparency—like hiring a personal chef instead of eating from a shared buffet—though it often requires higher minimums and can have different fee and liquidity implications.
pecuniary interest financial
"except to the extent of his/its pecuniary interest therein, if any"
Section 16 of the Securities Exchange Act of 1934 regulatory
"For purposes of Section 16 of the Securities Exchange Act of 1934, as amended"
A provision of federal securities law that requires company insiders—directors, officers and large shareholders—to publicly report their stock holdings and trades and to surrender any “short-swing” profits from purchases and sales within a six-month window. It acts like a rule that forces leaders to announce their trades and prevents quick buy-sell windfalls, giving investors transparency into insider activity and reducing opportunities for unfair gain.
SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
ADAR1 Capital Management, LLC

(Last)(First)(Middle)
3503 WILD CHERRY DRIVE
BUILDING 9

(Street)
AUSTIN TEXAS 78738

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
Rallybio Corp [ RLYB ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
DirectorX10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/18/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
Form filed by One Reporting Person
XForm filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock05/18/2026P6,009A$13.9759(1)916,152ISee Footnote(3)(4)
Common Stock05/19/2026P10,000A$13.9822(2)926,152ISee Footnote(3)(4)
Common Stock05/19/2026P200A$13.8926,352ISee Footnote(3)(4)
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
1. Name and Address of Reporting Person*
ADAR1 Capital Management, LLC

(Last)(First)(Middle)
3503 WILD CHERRY DRIVE
BUILDING 9

(Street)
AUSTIN TEXAS 78738

(City)(State)(Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer
DirectorX10% Owner
Officer (give title below)Other (specify below)
1. Name and Address of Reporting Person*
Schneeberger Daniel

(Last)(First)(Middle)
3503 WILD CHERRY DRIVE
BUILDING 9

(Street)
AUSTIN TEXAS 78738

(City)(State)(Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer
DirectorX10% Owner
Officer (give title below)Other (specify below)
Explanation of Responses:
1. The reported price is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $13.9100 to $14.0000, inclusive. Each Reporting Person undertakes to provide Rallybio Corp, any security holder of Rallybio Corp or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.
2. The reported price is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $13.9350 to $14.0000, inclusive. Each Reporting Person undertakes to provide to Rallybio Corp, any security holder of Rallybio Corp or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.
3. The reported securities are owned directly by private investment funds managed by ADAR1 Capital Management, LLC and separately managed accounts of ADAR1 Capital Management, LLC, and may be deemed to be indirectly beneficially owned by (i) ADAR1 Capital Management, LLC and (ii) Daniel Schneeberger, the sole manager of ADAR1 Capital Management, LLC.
4. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.
ADAR1 Capital Management, LLC By: Daniel Schneeberger, Manager /s/ Daniel Schneeberger05/20/2026
/s/ Daniel Schneeberger05/20/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider activity did Rallybio Corp (RLYB) report in this Form 4?

Rallybio reported that ADAR1-managed investment funds and accounts bought 16,209 shares of common stock in open-market transactions. These purchases, made over May 18–19, 2026, increased their indirect holdings to 926,352 shares, reflecting additional exposure by a 10% beneficial ownership group.

Who executed the recent Rallybio (RLYB) insider share purchases?

The shares were purchased by private investment funds and separately managed accounts managed by ADAR1 Capital Management, LLC. ADAR1 and Daniel Schneeberger, each a 10% owner, may be deemed indirect beneficial owners but both disclaim beneficial ownership beyond any pecuniary interest in these securities.

How many Rallybio (RLYB) shares did ADAR1-managed vehicles buy and at what prices?

ADAR1-managed vehicles bought 16,209 Rallybio common shares. Weighted average prices were reported near $13.98 per share, with individual trades occurring in ranges from $13.91 to $14.00, as detailed in the footnotes describing the multiple price points within each aggregated transaction.

What is the resulting Rallybio (RLYB) position after the Form 4 transactions?

After these purchases, the ADAR1-managed funds and accounts indirectly held 926,352 shares of Rallybio common stock. This figure reflects cumulative ownership following the three open-market purchases reported for May 18–19, 2026, and represents the updated position for this reporting group.

Are the Rallybio (RLYB) insider trades attributed personally to Daniel Schneeberger?

No, the securities are held by private funds and separately managed accounts run by ADAR1 Capital Management, LLC. Footnotes state Schneeberger may be deemed an indirect beneficial owner, but he and each reporting person disclaim beneficial ownership beyond any pecuniary interest in these holdings.

What do the weighted average prices in the Rallybio (RLYB) Form 4 mean?

Each reported price is a weighted average across multiple trades executed within a narrow price range. The footnotes specify ranges like $13.91 to $14.00 and commit to providing detailed trade-level prices upon request to Rallybio, investors, or SEC staff.