Merck & Co., Inc.
- SEC CIK
- 0000310158
- Latest filing
- Aug 7, 2026
The latest 13F from Merck & Co., Inc. covers Q2 2026 (filed Aug 7, 2026): 13 long positions worth $526.4M. The top 10 holdings make up 99.8% of the portfolio, and the largest is Personalis, Inc. (PSNL) at 35.8%. Livermore has 7 filings on Form 13F from this institution, going back to Q4 2024.
What changed in Q2 2026
Share counts compared with Q1 2026: how many positions were new, added to, reduced or sold out, and the biggest buys and sells. Dollar amounts are estimated at the quarter-end prices implied by the filing.
- New
- 3
- Est. +$25.6M
- Added
- 0
- Reduced
- 0
- Sold out
- 4
- Est. −$33.3M
Top 5 holdings
Share of this quarter's portfolio value
Biggest buys
New and added positions, by estimated amount bought
Biggest sells
Reduced and sold-out positions, by estimated amount sold
Metrics
13F metrics for Q2 2026, computed only from the numbers in the filings. Definitions below.
- Portfolio value
- $526.4M
- +$177.0M (+50.6%) vs. prior quarter
- Positions
- 13
- −1 vs. prior quarter
- Top 10 concentration
- 99.8%
- Top 10 as share of value
- Turnover
- 5.8%
- Q2 2026, one quarter
- Average holding period
- 6.2 quarters
- Weighted by value
How these are calculated
- Portfolio value: the market value of all long positions in the 13F, as reported at quarter end, excluding options.
- Top 10 concentration: the combined value of the 10 largest positions as a share of portfolio value.
- Turnover: the smaller of this quarter's estimated purchases and estimated sales, divided by the average of this and last quarter's portfolio value. Estimates multiply the change in shares by the quarter-end price implied by the filing (market value divided by shares); new positions use this quarter's value and sold-out positions last quarter's. Only positions reported in shares count, and it is not calculated when the previous quarter was not filed.
- Average holding period: how many consecutive quarters each current position has been held (including this one; a quarter without the position or without a filing starts the count over), weighted by this quarter's value. Counting starts with the first 13F in Livermore (Q4 2024), so positions held before then are understated.
13F filings by quarter
7 quarters, going back to Q4 2024. Bars show each quarter's 13F portfolio value; quarters without a filing are left blank.
Peak $526.4M (Q2 2026)
| Quarter | Filed | Positions | Value | Top 3 holdings | Changes | Filing |
|---|---|---|---|---|---|---|
| Q2 2026 | Aug 7, 2026 | 13 | $526.4M | PSNLMRNAKYMR | vs. Q1 2026 | SEC |
| Q1 2026 | May 13, 2026 | 14 | $349.4M | MRNAPSNLKYMR | vs. Q4 2025 | SEC |
| Q4 2025 | Feb 17, 2026 | 12 | $276.3M | PSNLMRNAKYMR | vs. Q3 2025 | SEC |
| Q3 2025 | Nov 12, 2025 | 13 | $228.0M | PSNLMRNAKYMR | vs. Q2 2025 | SEC |
| Q2 2025 | Aug 13, 2025 | 13 | $215.6M | PSNLMRNAKYMR | vs. Q1 2025 | SEC |
| Q1 2025 | May 14, 2025 | 12 | $164.3M | MRNAPSNLKYMR | vs. Q4 2024 | SEC |
| Q4 2024 | Feb 14, 2025 | 13 | $258.0M | MRNAPSNLKYMR | – | SEC |
13D and 13G filings
Companies where Merck & Co., Inc. reports owning 5% or more on Schedule 13D or 13G, and its latest filings.
Current stakes of 5% or more
2 companies, largest stake first.
Latest filings
7 filings on file made by Merck & Co., Inc. or listing it as a reporting person, newest first.
| Company | Filed (ET) | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| EVAXEvaxion A/S | Feb 3, 20254:15 PM ET | 13G/A | 19.96%63.0M shares | – | Jan 31, 2025 | SEC |
| PSNLPersonalis, Inc. | Dec 23, 20247:32 AM ET | 13G | 16.50%14.0M shares | New | Dec 19, 2024 | SEC |
| EVAXEvaxion A/S | Nov 6, 2024 | 13G/AOld format | – | – | – | SEC |
| EVAXEvaxion A/S | Jan 23, 2024 | 13GOld format | – | New | – | SEC |
| 4D Pharma PLC | Feb 2, 20225:21 PM ET | 13GOld format | – | New | – | SEC |
| Pandion Therapeutics, Inc. | Mar 4, 20216:06 AM ET | 13DOld format | – | New | – | SEC |
| KAKineta, Inc. | Jan 4, 20212:28 PM ET | 13GOld format | – | New | – | SEC |