Skip to content
Disclosery

Merck & Co., Inc.

Follow

13F filer, CIK 310158, RAHWAY, NJ

Merck & Co., Inc. reported $349,437,632 across 14 holdings for the quarter ended 2026-03-31, in a 13F-HR filed 2026-05-13. Its ten largest share positions make up 99.71% of the portfolio.

Filed (acceptance time not in the bulk data set), ingested 13F-HR 0000310158-26-000141

Period
2026-03-31
Reported value
$349M
Holdings
14
Top 10 weight
99.71%
New
3
Sold out
1

Part of the filer group Merck & Co., Inc.

How groups are built

Largest buys vs the previous quarter

SecurityShares changeApprox. value
EIKNnew+1,666,666$17.6M
AKTSnew+952,844$17M
XLOnew+105,982$891K
HURAadded+5,495$9.84K

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Largest sells vs the previous quarter

SecurityShares changeApprox. value
XLOexited-1,483,758-$950K

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Holdings, Q1 2026

Share positions as resolved from 13F-HR 0000310158-26-000141, largest first. % of portfolio is the value over $349,437,632, the sum of the share positions whose value is usable for ratios (method).

SecurityHistorySharesValue% of portfolioChangeLatest eventTimeline
MRNAMODERNA INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 2,308,190 shares; 2025Q1: 2,308,190 shares; 2025Q2: 2,308,190 shares; 2025Q3: 2,308,190 shares; 2025Q4: 2,308,190 shares; 2026Q1: 2,308,190 shares 2,308,190$117M33.56%0Timeline
PSNLPERSONALIS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 14,044,943 shares; 2025Q1: 14,044,943 shares; 2025Q2: 14,044,943 shares; 2025Q3: 14,044,943 shares; 2025Q4: 14,044,943 shares; 2026Q1: 14,044,943 shares 14,044,943$89.5M25.6%0Timeline
KYMRKYMERA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 772,165 shares; 2025Q1: 772,165 shares; 2025Q2: 772,165 shares; 2025Q3: 772,165 shares; 2025Q4: 772,165 shares; 2026Q1: 772,165 shares 772,165$64.3M18.4%0Timeline
ENTRADA THERAPEUTICS INCENTRADA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 1,739,768 shares; 2025Q1: 1,739,768 shares; 2025Q2: 1,739,768 shares; 2025Q3: 1,739,768 shares; 2025Q4: 1,739,768 shares; 2026Q1: 1,739,768 shares 1,739,768$22M6.28%0
EIKNEIKON THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 1,666,666 shares 1,666,666$17.6M5.05%newTimeline
AKTSAKTIS ONCOLOGY INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 952,844 shares 952,844$17M4.88%newTimeline
ALECALECTOR INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 3,545,719 shares; 2025Q1: 3,545,719 shares; 2025Q2: 3,545,719 shares; 2025Q3: 3,545,719 shares; 2025Q4: 3,545,719 shares; 2026Q1: 3,545,719 shares 3,545,719$7.62M2.18%0Timeline
SUTRO BIOPHARMA INCSUTRO BIOPHARMA INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 2,723,509 shares; 2025Q1: 2,723,509 shares; 2025Q2: 2,723,509 shares; 2025Q3: 2,723,509 shares; 2025Q4: 272,351 shares; 2026Q1: 272,351 shares 272,351$6.78M1.94%0
EVAXION BIOTECH A/SEVAXION BIOTECH A/SQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 542,279 shares; 2025Q1: 1,214,126 shares; 2025Q2: 1,214,126 shares; 2025Q3: 1,214,126 shares; 2025Q4: 1,214,126 shares; 2026Q1: 1,214,126 shares 1,214,126$4.52M1.29%0
VRDNVIRIDIAN THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 93,414 shares; 2025Q1: 93,414 shares; 2025Q2: 93,414 shares; 2025Q3: 93,414 shares; 2025Q4: 93,414 shares; 2026Q1: 93,414 shares 93,414$1.83M0.52%0Timeline
XLOXILIO THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 105,982 shares 105,982$891K0.26%newTimeline
CARMCARISMA THERAPEUTICS INC COMQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 1,473,240 shares; 2025Q1: 1,473,240 shares; 2025Q2: 1,473,240 shares; 2025Q3: 1,473,240 shares; 2025Q4: 1,473,240 shares; 2026Q1: 1,473,240 shares 1,473,240$47.9K0.01%0Timeline
NEUPNEUPHORIA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: 10,027 shares; 2025Q1: 10,027 shares; 2025Q2: 10,027 shares; 2025Q3: 10,027 shares; 2025Q4: 10,027 shares; 2026Q1: 10,027 shares 10,027$40.8K0.01%0Timeline
HURATUHURA BIOSCIENCES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q2: restricted; 2024Q3: not loaded; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: 13,950 shares; 2025Q3: 13,950 shares; 2025Q4: 13,950 shares; 2026Q1: 19,445 shares 19,445$34.8K0.01%+5,495Timeline

Sold out in Q1 2026

Positions in the previous quarter's report that this quarter's report no longer lists.

SecurityShares beforeValue beforeType
XLOXilio Therapeutics Inc.1,483,758$950Kshares

How Q1 2026 was built

Available 13F filings of this filer for the quarter and their roles: the base report is the latest original or restatement, NEW HOLDINGS amendments filed after it are added (method).

FilingRoleAmendmentFiledAcceptedIngested
13F-HR 0000310158-26-000141 base2026-05-13acceptance time not in the bulk data set