Rallybio Corporation - Common Stock, par value $0.0001 per share (RLYB)

Q: What does CUSIP 75120L100 represent in this 13F holders report?

CUSIP 75120L100 is the security identifier for RLYB - Rallybio Corporation - Common Stock, par value $0.0001 per share used to aggregate holder disclosures.

Q: How many institutions held RLYB - Rallybio Corporation - Common Stock, par value $0.0001 per share in Q4 2023?

53 institutional investors reported RLYB - Rallybio Corporation - Common Stock, par value $0.0001 per share for Q4 2023. Use the holders table for investor-level position and value details.

CUSIP: 75120L100

Q4 2023 13F Holders as of 31 Dec 2023

Security type / class: Equity / Common Stock, par value $0.0001 per share
Total 13F shares: 31,751,116
Total 13F value: $75,885,524
Share change: +938,481
SEC-reported price per share: $2.39
Number of holders: 53
Value change: +$1,489,758
Number of buys: 28
Number of sells: 23
Shares outstanding: 5,294,835

Security key

75120L100

Report period

Q4 2023

Institutions

Top holders

RLYB full security history Ownership snapshot Full 13F holder table Newer quarter: Q3 2025 Rallybio Corp SEC filings Rallybio Corp company facts

Broader feeds

Latest 13F filings Latest 13D/G filings Investors directory

Reporting periods

Holder history for CUSIP 75120L100

Newer quarter: Q3 2025

Recent filing periods:

Q1 2026 Q4 2025 Q3 2025

Ownership snapshot

Top reported holders of RLYB - Rallybio Corporation - Common Stock, par value $0.0001 per share (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Comparable stake leader

5AM Opportunities I, L.P.

Disclosed value leader

5AM Opportunities I, L.P.

Comparable rows

0/15

Latest evidence

30 Sep 2023

3/4/5 13F Highest disclosed value: $30,591,937 15 rows are not safely comparable across share classes. Showing 1-6 of 15 holder rows.

Quick read

5AM Opportunities I, L.P. has the largest disclosed position value at $30.59M.

0 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.

Open SEC evidence Opens 5AM Opportunities I, L.P.'s linked filing trail.

Disclosed position value Top 5

5AM Opportunities I, L.P. $30.59M

5AM Partners V, LLC $29.77M

5AM Ventures V, L.P. $22.83M

VIKING GLOBAL INVESTORS LP $14.14M

5AM Venture Management, LLC $12.24M

Value bars compare disclosed positions; verify each figure against the linked filing evidence.

Detailed SEC evidence table Showing 1-6 of 15 holder rows

Holder	Evidence	Ownership %	Position	12M Net Δ	As of
5AM Opportunities I, L.P.	3/4/5 10%+ Owner 3/4/5	— denominator unverified	$30,591,937 3,730,724 shares	—	03 Jun 2022
5AM Partners V, LLC	3/4/5 10%+ Owner 3/4/5	— denominator unverified	$29,771,937 3,630,724 shares	—	07 Mar 2023
5AM Ventures V, L.P.	3/4/5 10%+ Owner 3/4/5	— denominator unverified	$22,833,933 2,784,626 shares	—	29 Jul 2021
VIKING GLOBAL INVESTORS LP	13F 3/4/5 Company · 10%+ Owner 13F 3/4/5	— denominator unverified	$14,136,398 4,194,777 shares	—	30 Sep 2023
5AM Venture Management, LLC	13F Company 13F	— denominator unverified	$12,235,540 3,630,724 shares	—	30 Sep 2023
New Leaf Venture Partners, L.L.C.	13F Company 13F	— denominator unverified	$11,126,402 3,301,603 shares	—	30 Sep 2023

How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

13F holder rows

Institutional holders as of Q4 2023

Investor-level positions for this CUSIP, loaded as an interactive table.

Institutions

31,751,116

Rows available

Investor	Option	Weight %	Change %	SEC-reported value	* Price	Shares	Share Change	Activity	Report Period

^* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.

Compare Q4 2023 vs Q4 2025 Across Filers

Q4 2025 holders

Q4 2023 holders

Holder diff

Investor	Q4 2025 Shares	Q4 2023 Shares	Share Diff	Share Chg %	Q4 2025 value	Q4 2023 value	Value change	Value Chg %

Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).

Quarterly Holders Trend

Quarterly Value Trend

Quarterly Shares Trend