InvestorLens

MRK — MERCK & CO INC

Health Care · Drug Manufacturers

Sign in to save5 tracked investors reported this
For educational research only.InvestorLens analyzes public regulatory filings (SEC EDGAR, STOCK Act PTRs) that may be delayed by 45 days or more. Information shown is historical and is not financial, legal, or tax advice, nor a recommendation or solicitation to buy or sell any security. Always do your own research.

InvestorLens aggregates public filing data to show which tracked investors reported holdings in this stock. Dollar values represent reported position values, not market capitalization, and may be delayed up to 45 days. Not a recommendation.

Sourced from SEC EDGAR public filings

Why are billionaires buying MRK?

Built from public SEC filings and public economic data. Not a recommendation.

Confidence
95
Institutional Conviction
Net accumulation · 1 buying vs 0 selling last quarter
68
Macro Tailwind
Macro conditions are mixed for this sector
55
Congressional Activity
0 congressional purchases, 1 sale disclosed in the last 6 months
Why? — Evidence & Confidence ▾

Of 1 tracked investors who changed their MRK position last quarter, 1 bought and 0 sold (100% buy-side). Macro conditions are mixed for this sector (Macro Tailwind 55/100 in a Squeeze regime). 0 congressional purchases, 1 sale disclosed in the last 6 months.

Supporting evidence
  • +1 tracked investor added or increased positions last quarter (Izzy Englander)
  • +5 tracked investors reported holding MRK at their latest filing
  • +Macro Health is 52/100 in a Squeeze regime — historically acceptable for Health Caresource
Contradicting evidence — always shown
  • −Congressional disclosures lean toward selling (1 sales vs 0 purchases, 6 months)
  • −13F data is disclosed up to 45 days after quarter end — positions may have changed since
Know the limits
  • · 13F disclosure lag (up to 45 days)
  • · Tracked investors are a sample, not the whole market
  • · Sector regime fit is a historical average, not a guarantee

Every InvestorLens score shows its evidence — including what argues against it. Model conviction-v1 · generated 8/4/2026.

About MERCK & CO INC (MRK)

MERCK & CO INC (MRK) appears in the most recent 13F filings of 5 tracked institutional investors. MERCK & CO INC is classified in the Health Care sector (Drug Manufacturers industry). The largest disclosed position is held by Ken Griffin (Citadel Advisors), valued at $1.6B. Across recent filings, tracked investors recorded 2 new positions, 0 increased, 0 reduced, and 1 exited. All data sourced from SEC 13F filings.

Smart Money Consensus™

Based on recent institutional activity in MRK

67
/100
Institutional Accumulation
Added / Increased2
Reduced0
Exited1
BearishBullish
Crowded Trade Score™

How many top investors track MRK

33
/100
Emerging Interest
5investors

A small number of top investors own this.

UndiscoveredCrowded
151015+

MRK Ownership Composition

How MERCK & CO INC is held across tracked investor types, based on reported 13F positions.

Dominant Type
Other
94% of tracked value
Institutions
5
tracked investors
Total Reported
$2.3B
combined 13F value
Sectors2
  • Other93.9%
  • Hedge Funds6.1%
Other(4)
93.9%
Hedge Funds(1)
6.1%

Tracked investors reporting MRK

  • Ken GriffinMar 31, 2026
    Citadel Advisors
    Shares
    13.1M
    Value
    $1.6B
    % Portfolio
    0.26%
  • Izzy EnglanderMar 31, 2026
    Millennium Management
    Shares
    3.8M
    Value
    $462.6M
    % Portfolio
    0.19%
  • Steve CohenMar 31, 2026
    Point72 Asset Management
    Shares
    1.2M
    Value
    $138.8M
    % Portfolio
    0.18%
  • Paul Tudor JonesMar 31, 2026
    Tudor Investment Corp
    Shares
    751.6K
    Value
    $90.4M
    % Portfolio
    0.17%
  • Ray DalioDec 31, 2025
    Bridgewater Associates
    Shares
    310.2K
    Value
    $32.7K
    % Portfolio
    0.00%

Recent activity

Frequently asked questions

How many institutional investors hold MRK?
5 tracked institutional investors disclosed a position in MRK (MERCK & CO INC) in their most recent 13F filing.
Who is the largest institutional holder of MRK?
Ken Griffin, Citadel Advisors, holds the largest disclosed position in MRK, valued at $1.6B.
Did institutional ownership of MRK increase or decrease?
Across recent 13F filings, tracked investors recorded 2 new positions, 0 increased, 0 reduced, and 1 fully exited MRK.
What sector is MRK in?
MERCK & CO INC is classified in the Health Care GICS sector, Drug Manufacturers industry.
Where does this MRK ownership data come from?
SEC Form 13F-HR filings, accessed via EDGAR. 13F filings are disclosed quarterly with a 45-day reporting delay and cover U.S.-listed long equity positions only. This is not investment advice.