VANGUARD GROUP INC
Rank #1
10.3%
- Shares
- 254.32M
- Change
- +2.19M
- Change %
- +87.00%
- Filing
- Dec 31, 2025
Increased
Methodology published · Market data, model notes, and corrections process are public · Data policy · Corrections policy
NYSE · HEALTHCARE · Holders
Merck & Company Inc (MRK) Institutional Ownership & Insider Trading History
Top MRK institutional shareholders, filing changes, and Form 4 insider activity with filters for buys, sales, option exercises, gifts, and tax withholding.
Section freshness
Price Jun 26, 4:03 PM EDT · Statements Mar 30, 8:00 PM EDT
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Data freshness
Prices update fastest. Fundamentals, analyst data, and news update on their own schedules, so check these timestamps before comparing signals.
Price time means the latest available trade or regular-market close. Other times show when that section was checked or published.
PriceLive
Last traded •
Source: Market data provider
Fundamentalsevery 1 day
Provider checked •
Source: Market data provider
Analystevery 1 hr
Provider checked •
Source: Market data provider
Newsevery 15 min
Latest item •
Source: Market data provider
Ownership read
MRK insider sentiment: Mixed, buy-heavy.
VANGUARD GROUP INC is the largest institutional holder. 53 sales and 67 purchases appear in the recent Form 4 filings. Use the filters below to separate real buying and selling from option exercises, gifts, awards, and tax withholding.
Insider flow
MRK
Purchases963.19K
Sales602.19K
Directional bars ignore awards, gifts, conversions, and tax withholding rows.
Top holder
254.32M
VANGUARD GROUP INC
Insider stance
Mixed, buy-heavy
$43.30M sold / $31.78M bought
Latest filing
May 29, 2026
Most recent holder or insider filing date
Filings shown
240
120 holder / 120 insider
- Holder rows
- 120
- Market data source
- Latest filing
- May 29, 2026
- Most recent holder or insider filing date
- Increased / initiated
- 57
- 60 decreased
- Insider rows
- 120
- Market data source
Top 120 institutional holders
Merck & Company Inc (MRK) institutional ownership
Ranked by reported share count, with position changes and latest filing dates where ownership data supplies them.
BLACKROCK
Rank #2
9.11%
- Shares
- 225.83M
- Change
- +6.73M
- Change %
- +3.07%
- Filing
- Mar 31, 2026
Increased
VANGUARD CAPITAL MANAGEMENT LLC
Rank #3
6.50%
- Shares
- 160.99M
- Change
- +160.99M
- Change %
- —
- Filing
- Mar 31, 2026
Initiated
STATE STREET CORP
Rank #4
4.82%
- Shares
- 119.33M
- Change
- -714.50K
- Change %
- -59.00%
- Filing
- Mar 31, 2026
Decreased
WELLINGTON MANAGEMENT GROUP LLP
Rank #5
3.40%
- Shares
- 84.31M
- Change
- -2.12M
- Change %
- -2.45%
- Filing
- Mar 31, 2026
Decreased
VANGUARD PORTFOLIO MANAGEMENT LLC
Rank #6
2.72%
- Shares
- 67.30M
- Change
- +67.30M
- Change %
- —
- Filing
- Mar 31, 2026
Initiated
GEODE CAPITAL MANAGEMENT
Rank #7
2.40%
- Shares
- 59.56M
- Change
- -489.83K
- Change %
- -82.00%
- Filing
- Mar 31, 2026
Decreased
JPMORGAN CHASE & CO
Rank #8
2.14%
- Shares
- 52.97M
- Change
- +23.77M
- Change %
- +81.41%
- Filing
- Mar 31, 2026
Increased
CHARLES SCHWAB INVESTMENT MANAGEMENT INC
Rank #9
2.01%
- Shares
- 49.77M
- Change
- +1.20M
- Change %
- +2.47%
- Filing
- Mar 31, 2026
Increased
MORGAN STANLEY
Rank #10
1.92%
- Shares
- 47.63M
- Change
- +2.69M
- Change %
- +5.98%
- Filing
- Mar 31, 2026
Increased
FMR LLC
Rank #11
1.80%
- Shares
- 44.52M
- Change
- +3.68M
- Change %
- +9.01%
- Filing
- Mar 31, 2026
Increased
NORGES BANK
Rank #12
1.53%
- Shares
- 37.98M
- Change
- +1.87M
- Change %
- +5.18%
- Filing
- Dec 31, 2025
Increased
BANK OF AMERICA CORP
Rank #13
1.24%
- Shares
- 30.77M
- Change
- +2.92M
- Change %
- +10.48%
- Filing
- Mar 31, 2026
Increased
NORTHERN TRUST CORP
Rank #14
1.09%
- Shares
- 27.09M
- Change
- -144.62K
- Change %
- -53.00%
- Filing
- Mar 31, 2026
Decreased
FISHER ASSET MANAGEMENT
Rank #15
1.07%
- Shares
- 26.44M
- Change
- +1.56M
- Change %
- +6.28%
- Filing
- Mar 31, 2026
Increased
PRICE T ROWE ASSOCIATES INC
Rank #16
0.93%
- Shares
- 23.04M
- Change
- +4.29M
- Change %
- +22.87%
- Filing
- Mar 31, 2026
Increased
INVESCO LTD.
Rank #17
0.88%
- Shares
- 21.86M
- Change
- +1.31M
- Change %
- +6.37%
- Filing
- Mar 31, 2026
Increased
UBS AM
Rank #18
0.82%
- Shares
- 20.41M
- Change
- +981.42K
- Change %
- +5.05%
- Filing
- Mar 31, 2026
Increased
GOLDMAN SACHS GROUP INC
Rank #19
0.81%
- Shares
- 20.13M
- Change
- +784.66K
- Change %
- +4.05%
- Filing
- Mar 31, 2026
Increased
LEGAL & GENERAL GROUP PLC
Rank #20
0.79%
- Shares
- 19.54M
- Change
- -238.30K
- Change %
- -121.00%
- Filing
- Mar 31, 2026
Decreased
| # | Institution | % held | Shares | Change | Change % | Filing date |
|---|---|---|---|---|---|---|
| 1 | 10.3% | 254.32M | +2.19M Increased | +87.00% | Dec 31, 2025 | |
| 2 | 9.11% | 225.83M | +6.73M Increased | +3.07% | Mar 31, 2026 | |
| 3 | 6.50% | 160.99M | +160.99M Initiated | — | Mar 31, 2026 | |
| 4 | 4.82% | 119.33M | -714.50K Decreased | -59.00% | Mar 31, 2026 | |
| 5 | 3.40% | 84.31M | -2.12M Decreased | -2.45% | Mar 31, 2026 | |
| 6 | 2.72% | 67.30M | +67.30M Initiated | — | Mar 31, 2026 | |
| 7 | 2.40% | 59.56M | -489.83K Decreased | -82.00% | Mar 31, 2026 | |
| 8 | 2.14% | 52.97M | +23.77M Increased | +81.41% | Mar 31, 2026 | |
| 9 | 2.01% | 49.77M | +1.20M Increased | +2.47% | Mar 31, 2026 | |
| 10 | 1.92% | 47.63M | +2.69M Increased | +5.98% | Mar 31, 2026 | |
| 11 | 1.80% | 44.52M | +3.68M Increased | +9.01% | Mar 31, 2026 | |
| 12 | 1.53% | 37.98M | +1.87M Increased | +5.18% | Dec 31, 2025 | |
| 13 | 1.24% | 30.77M | +2.92M Increased | +10.48% | Mar 31, 2026 | |
| 14 | 1.09% | 27.09M | -144.62K Decreased | -53.00% | Mar 31, 2026 | |
| 15 | FISHER ASSET MANAGEMENT | 1.07% | 26.44M | +1.56M Increased | +6.28% | Mar 31, 2026 |
| 16 | 0.93% | 23.04M | +4.29M Increased | +22.87% | Mar 31, 2026 | |
| 17 | 0.88% | 21.86M | +1.31M Increased | +6.37% | Mar 31, 2026 | |
| 18 | 0.82% | 20.41M | +981.42K Increased | +5.05% | Mar 31, 2026 | |
| 19 | 0.81% | 20.13M | +784.66K Increased | +4.05% | Mar 31, 2026 | |
| 20 | 0.79% | 19.54M | -238.30K Decreased | -121.00% | Mar 31, 2026 |
Showing 20 of 120 matching institutional rows.Load more institutions
Recent insider transactions
Merck & Company Inc (MRK) Form 4 filings
Action codes are translated so open-market buys and sales are separate from awards, gifts, conversions, and tax withholding.
KARSANBHAI, SURENDRALAL LANCA
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
COE, MARY ELLEN
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
THULIN, INGE G
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
SEIDMAN, CHRISTINE E
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
RUSSO, PATRICIA F
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
WARDEN, KATHY J
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
BAKER, DOUGLAS M JR
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
CRAIG, PAMELA J.
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
GLOCER, THOMAS H
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
LAVIZZO-MOUREY, RISA J
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
MAYO, STEPHEN
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
ROTHMAN, PAUL
Director
- Shares
- 1.85K
- % company
- <0.01%
- Price
- $118.72
- Value
- $220,000
Filed May 29, 2026
| # | Insider | % company | Action | Shares | Price | Value | Filing date |
|---|---|---|---|---|---|---|---|
| 1 | KARSANBHAI, SURENDRALAL LANCA Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 2 | COE, MARY ELLEN Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 3 | THULIN, INGE G Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 4 | SEIDMAN, CHRISTINE E Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 5 | RUSSO, PATRICIA F Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 6 | WARDEN, KATHY J Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 7 | BAKER, DOUGLAS M JR Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 8 | CRAIG, PAMELA J. Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 9 | GLOCER, THOMAS H Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 10 | LAVIZZO-MOUREY, RISA J Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 11 | MAYO, STEPHEN Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
| 12 | ROTHMAN, PAUL Director | <0.01% | PurchaseOpen-market or direct purchase reported on Form 4. | 1.85K | $118.72 | $220,000 | May 29, 2026 |
Showing 12 of 120 matching Form 4 rows. Percent of company uses current shares outstanding when available.Load more insiders
Frequently asked
Common questions.
Who are the largest MRK shareholders?
VANGUARD GROUP INC is the largest institutional holder of MRK, with 254.32 million shares, or about 10.26% of shares outstanding. Additional institutions are ranked by reported share count.
What is institutional ownership of MRK?
Merck & Company Inc (MRK) has 120 institutional holders on file — 57 that increased or initiated positions and 60 that reduced them, as of the latest filing on Mar 31, 2026.
Where can I see Merck & Company Inc insider transactions?
Merck & Company Inc (MRK) has 120 Form 4 insider transactions on file, most recently on May 29, 2026, separated into purchases, sales, option exercises, awards, gifts, and tax withholding so administrative transactions are distinguished from open-market trades.
Are MRK insiders buying or selling?
Recent MRK insider activity reads Mixed, buy-heavy: 53 sales and 67 purchases. Awards, gifts, conversions, and tax withholding are listed separately because they do not carry the same signal as open-market trades.
Who is the most active MRK insider?
ZACHARY, JENNIFER is the most active MRK insider by absolute share movement, with 419,451 shares moving across the filing history. Review the action labels before treating that activity as buying or selling.