HolderBook

RALLYBIO CORP (RLYB)

Institutional ownership reported to the SEC as of Q2 2026, across 20 quarters.

38
Reporting holders
$81.0M
Reported value
225.5%
Of shares outstanding
0.0%
Calls
0.0%
Puts
+0
Holder change

Institutions report 11,973,648 shares against 5,310,499 outstanding. Shares only - option lines are excluded, which is why this can be compared with the company at all. The count comes from the cover page of the company's own most recent report, so it is dated when that was filed rather than at quarter end. Over 100% because an adviser and a sub-adviser can both report the same shares, and both are counted.

Calls and puts are the parts of reported value carried in derivative lines rather than shares, and they point in opposite directions: a manager holding calls is positioned for the security, one holding puts against it - or hedging shares they already own, which is why index funds carry so many. Most sites add the two together and report one figure, which averages away the only interesting part.

Holders

Download these holders as CSV

FilerValueShares Their book Held Change
ADAR1 Capital Management, LLC$14.8M926,3520.68%2q+4411.1%+$14.5M
CITADEL ADVISORS LLC$13.9M7,777,987?0.00%2q
FMR LLC$12.7M794,7200.00%2qHELD
VIKING GLOBAL INVESTORS LP$8.4M524,3470.02%2qHELD
TPG GP A, LLC$6.1M378,5510.12%2qHELD
Nantahala Capital Management, LLC$6.0M376,8440.10%2q+25.3%+$1.2M
Pivotal bioVenture Partners Investment Advisor LLC$4.8M300,5791.56%2qHELD
RENAISSANCE TECHNOLOGIES LLC$3.2M199,9070.00%2q+27.7%+$694.1K
VANGUARD CAPITAL MANAGEMENT LLC$2.8M172,4970.00%2q+54.0%+$967.3K
Almitas Capital LLC$1.9M120,6820.46%2q-36.9%-$1.1M
Rangeley Capital, LLC$1.7M104,8501.53%2q+248.0%+$1.2M
Mariner, LLC$809.1K50,5660.00%2qHELD
JANE STREET GROUP, LLC$758.8K47,4230.00%newNEW
GEODE CAPITAL MANAGEMENT, LLC$512.9K32,0470.00%2q-9.5%-$54.1K
BlackRock, Inc.$485.3K30,3320.00%2q+73.5%+$205.5K
STATE STREET CORP$415.9K25,9920.00%newNEW
HRT FINANCIAL LP$410.0K25,6570.00%newNEW
XTX Topco Ltd$344.0K21,4970.00%2q+91.5%+$164.3K
VANGUARD FIDUCIARY TRUST CO$269.1K16,8200.00%2q+24.2%+$52.4K
TWO SIGMA INVESTMENTS, LP$265.9K16,6190.00%newNEW
Quadrature Capital Ltd$207.9K12,9950.00%newNEW
DIMENSIONAL FUND ADVISORS LP$180.5K11,2800.00%2qHELD
Vanguard Global Advisers, LLC$23.1K1,4420.00%2qHELD
MERCER GLOBAL ADVISORS INC /ADV$20.0K1,2500.00%newNEW
Hartford Financial Management Inc.$13.0K8120.00%2qHELD
SBI Securities Co., Ltd.$8.1K5060.00%2q-3.4%
Caitong International Asset Management Co., Ltd$6.9K4340.00%newNEW
UBS Group AG$2.3K1460.00%2q-98.2%-$124.3K
Truvestments Capital LLC$2.1K1290.00%newNEW
MORGAN STANLEY$2.0K1250.00%2q-0.8%
BNP PARIBAS FINANCIAL MARKETS$1.9K1200.00%2qHELD
Fortitude Family Office, LLC$848530.00%2qHELD
WELLS FARGO & COMPANY/MN$592370.00%2q-50.0%
EverSource Wealth Advisors, LLC$496310.00%newNEW
JPMORGAN CHASE & CO$14590.00%2q-99.6%-$40.1K
Allworth Financial LP$9660.00%2qHELD
BARCLAYS PLC$4830.00%newNEW
DANSKE BANK A/S$1610.00%2qHELD

Five percent filings

Anyone crossing 5% of a company must say so within days - far sooner than the next quarterly holdings report. A 13D declares an intent to influence the company; a 13G is the passive version. See all activist filings →

FiledFormFiler % of class
2026-08-1413G/ANantahala Capital Management, LLCwith 2 co-filers3.6%
2026-08-1413G/ABALYASNY ASSET MANAGEMENT L.P.with 4 co-filers0.0%
2026-08-1413G/ACormorant Asset Management, LPwith 1 co-filers0.0%
2026-08-0613G/AFMR LLCwith 1 co-filers15.0%
2026-08-0413G/ALaurion Capital Management LPwith 2 co-filers0.0%

What the company announced

Form 8-K filings from the last 120 days, showing only the items worth a reader's attention. Earnings releases, exhibit attachments and general disclosures are filed constantly and are left out. Filed is when the SEC received it; event is the date the company says the thing happened.

FiledEvent dateWhatSource
2026-09-092026-09-08Directors or officers departed or appointedfiling

What the insiders did

Open market purchases and sales reported on Form 4 in the last 180 days. Grants, option exercises and shares surrendered to cover tax are left out: they are compensation rather than a decision to buy or sell. Where a broker filled one order in tranches the lines are summed, because it was one decision.

Ten percent owners and entities

Usually an institution that crossed a reporting threshold, or a company taking a strategic stake, rather than an individual with a view.

DateInsiderRoleSideSharesValue
2026-05-04ADAR1 Capital Management, LLC10% ownerBought120,804$1.7M ×2
2026-05-13ADAR1 Capital Management, LLC10% ownerBought79,259$1.1M ×2
2026-05-11ADAR1 Capital Management, LLC10% ownerBought50,000$700.0K ×3
2026-05-05ADAR1 Capital Management, LLC10% ownerBought35,101$491.3K
2026-05-19ADAR1 Capital Management, LLC10% ownerBought10,200$142.6K ×2

Quarter by quarter

Coverage begins with the quarter ending 2018-12-31. Earlier filings exist only as occasional late amendments, too sparse to describe a market, so they are not shown.

QuarterHoldersValue SharesNewAdded TrimmedOptions
Q2 202638$81.0M11,973,64810970.0%
Q1 202638$41.9M4,666,44435000.0%
Q4 202546$20.7M24,931,16857110.0%
Q3 202545$14.9M29,833,37169110.0%
Q2 202548$10.5M31,192,73877120.0%
Q1 202547$20.9M32,001,26227120.0%
Q4 202449$31.1M32,428,35341190.0%
Q3 202449$36.5M31,213,634111210.0%
Q2 202463$39.6M29,573,9191912160.0%
Q1 202460$56.2M30,367,3381214160.0%
Q4 202353$71.2M29,810,74592070.0%
Q3 202358$105.2M31,203,726412130.0%
Q2 202359$188.3M33,261,4351122120.0%
Q1 202351$201.9M35,359,014318120.0%
Q4 202257$212.3M32,313,982926110.0%
Q3 202252$402.1M27,791,4031012150.0%
Q2 202245$208.8M27,659,986414160.0%
Q1 202247$193.9M27,776,263101580.0%
Q4 202138$260.1M27,428,81841540.0%
Q3 202134$419.9M24,054,39534000.0%