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MRK in the 13F filings

Merck & Co Inc · CUSIP 58933Y105

Sector · Pharmaceuticals and biotechnologyTheme · Healthcare: biopharma and medtech· L3VLUP-definedTheme · Pharmaceutical preparations
Quarter
Q3 2026 · early filersQ2 2026Q1 2026Q4 2025Q3 2025Q2 2025Q1 2025Q4 2024Q3 2024Q2 2024Q1 2024Q4 2023
Quarter end
31 Mar 2025
the date the book describes
Filed
5 Nov 2026
latest of these filings; the earliest 2 May 2025
Managers listing it
36
at least, of 95 tracked, among listed positions
Comparable managers
95
filed both Q4 2024 and Q1 2025; 30 listed it in both
Shares listed
231,796,651
combined, among listed positions
Reported value
$20.8bn
combined, at the quarter end

Among the 95 comparable managers: 20 buyers (opened or added shares) and 18 sellers (trimmed or exited), at least, among listed positions. Their net change in shares is not known from listed positions, because at least one of them lists it in only one of the two quarters.

Managers listing MRK in Q1 2025

Share of 13F value is the position’s reported value over everything the manager reported that quarter. The share change is against Q4 2024, and only where both filings list the position. A rise in value with no rise in shares is the price, not buying.

36 of 36 holders

ActionFiling
Wellington Management Group LLP81,669,651$7.3bn1.41%Added+927,62113 May 2025 (the filing on sec.gov)
Fidelity (FMR LLC)31,808,043$2.9bn0.18%Trimmed-5,552,5295 Nov 2026 (the filing on sec.gov)
Invesco Ltd15,298,134$1.4bn0.26%Trimmed-154,10612 May 2025 (the filing on sec.gov)
Arrowstreet Capital LP14,362,008$1.3bn1.05%Added+7,888,91414 May 2025 (the filing on sec.gov)
T. Rowe Price Associates Inc11,765,832$1.1bn0.13%Trimmed-745,17514 May 2025 (the filing on sec.gov)
AllianceBernstein LP10,236,395$919m0.33%Trimmed-873,28415 May 2025 (the filing on sec.gov)
D. E. Shaw & Co.9,311,726$836m0.74%Added+2,936,92215 May 2025 (the filing on sec.gov)
MFS Investment Management7,983,193$717m0.24%Trimmed-214,4942 May 2025 (the filing on sec.gov)
AQR Capital Management LLC7,757,818$691m0.71%Added+2,380,06615 May 2025 (the filing on sec.gov)
Harris Associates LP7,469,360$670m1.13%Added+1,224,91015 May 2025 (the filing on sec.gov)
Squarepoint Ops LLC3,875,934$348m0.42%Added+2,036,84127 Aug 2025 (the filing on sec.gov)
Millennium Management LLC3,524,602$316m0.17%Trimmed-56,36115 May 2025 (the filing on sec.gov)
Two Sigma Advisers LP3,288,600$295m0.66%Trimmed-1,598,50015 May 2025 (the filing on sec.gov)
Capital Research Global Investors3,150,734$283m0.06%Trimmed-1,322,65112 May 2025 (the filing on sec.gov)
Janus Henderson Group Ltd2,765,366$247m0.14%Trimmed-3,099,13915 May 2025 (the filing on sec.gov)
Acadian Asset Management LLC2,594,693$233m0.66%Added+2,027,95721 May 2025 (the filing on sec.gov)
Man Group PLC2,507,856$225m0.57%Added+1,246,95015 May 2025 (the filing on sec.gov)
Two Sigma Investments LP2,200,701$198m0.42%Added+271,87215 May 2025 (the filing on sec.gov)
Citadel Advisors LLC2,048,739$184munder 0.1%Trimmed-3,232,97115 May 2025 (the filing on sec.gov)
Voloridge Investment Management LLC1,673,894$150m0.56%Trimmed-646,91215 May 2025 (the filing on sec.gov)
Artisan Partners LP1,327,248$119m0.19%Added+273,37214 May 2025 (the filing on sec.gov)
Neuberger Berman Group LLC1,317,117$118m0.10%Trimmed-69,31027 Oct 2026 (the filing on sec.gov)
Tudor Investment Corp774,203$69m0.23%Addedn.a.15 May 2025 (the filing on sec.gov)
Woodline Partners LP764,526$69m0.45%Added+33,19215 May 2025 (the filing on sec.gov)
Schonfeld Strategic Advisors LLC566,604$51m0.31%Added+124,96215 May 2025 (the filing on sec.gov)
Page 1 of 2

Largest increases and reductions, by shares

Q4 2024 to Q1 2025, among managers that listed it in both quarters or opened it.

Increases

Reductions

New positions and exits

At least these many: a manager is shown exiting only where its own filing shows the position gone.

New (4)

Exited (2)

Ownership over time

Every quarter on file. A quarter-end value moves with the price as well as with the shares held; buyers and sellers count comparable managers, by shares.
38 in Q3 2024 to 25 in Q2 2026

Tracked managers listing it, at least.

02040602014201620182020202220242026
the quarter shown share split complete books; unmarked quarters rest on listed positionsClick a quarter to open it.
MRK by quarter
QuarterHoldersReported valueBuyersSellers
Q2 201323$25.9bnn.a.n.a.
Q3 201324$25.4bnn.a.n.a.
Q4 201323$27.1bnn.a.n.a.
Q1 201424$31.2bnn.a.n.a.
Q2 201428$30.6bnn.a.n.a.
Q3 201432$30.5bnn.a.n.a.
Q4 201430$28.6bnn.a.n.a.
Q1 201529$28.8bnn.a.n.a.
Q2 201529$27.1bnn.a.n.a.
Q3 201525$23.0bnn.a.n.a.
Q4 201528$23.9bnn.a.n.a.
Q1 201628$23.8bnn.a.n.a.
Q2 201627$25.9bnn.a.n.a.
Q3 201627$27.5bnn.a.n.a.
Q4 201626$24.4bnn.a.n.a.
Q1 201731$24.7bnn.a.n.a.
Q2 201734$24.0bnn.a.n.a.
Q3 201731$23.7bnn.a.n.a.
Q4 201732$20.0bnn.a.n.a.
Q1 201830$17.5bnn.a.n.a.
Q2 201827$19.3bnn.a.n.a.
Q3 201827$22.9bnn.a.n.a.
Q4 201826$24.4bnn.a.n.a.
Q1 201926$24.4bnn.a.n.a.
Q2 201928$23.3bnn.a.n.a.
Q3 201931$23.2bnn.a.n.a.
Q4 201934$24.0bnn.a.n.a.
Q1 202033$18.5bnn.a.n.a.
Q2 202034$18.6bnn.a.n.a.
Q3 202035$20.2bnn.a.n.a.
Q4 202034$19.1bnn.a.n.a.
Q1 202133$16.6bnn.a.n.a.
Q2 202131$15.1bnn.a.n.a.
Q3 202131$15.2bnn.a.n.a.
Q4 202126$15.0bnn.a.n.a.
Q1 202234$17.4bnn.a.n.a.
Q2 202234$19.0bnn.a.n.a.
Q3 202235$17.2bnn.a.n.a.
Q4 202235$25.2bnn.a.n.a.
Q1 202333$26.6bnn.a.n.a.
Q2 202334$30.1bnn.a.n.a.
Q3 202339$26.7bnn.a.n.a.
Q4 202341$29.3bn2220
Q1 202437$37.1bn2119
Q2 202438$33.0bn2118
Q3 202438$29.1bn2317
Q4 202435$23.7bn1819
Q1 202536$20.8bn2018
Q2 202531$18.5bn1813
Q3 202536$19.0bn1818
Q4 202532$26.8bn2519
Q1 202630$28.9bn1327
Q2 202625$29.2bn1424

Compare with…

Holders over time, buyers and sellers, and the managers holding both, side by side for up to four stocks.

MRK and LLY →MRK and JNJ →MRK and VRTX →Choose a stock to compare with MRK →

How much of the picture this is

A 13F is a manager’s long US-listed equity book at a quarter end, filed up to 45 days later. It shows no shorts, cash, bonds or performance, and it is never today’s portfolio. Large books are listed to their largest positions, so a manager missing from this table may still hold a small position below that line. These are 95 tracked managers, not the institutional market.

Which funds own MRK, latest filings →Back to the 13F Explorer →