MERCK & CO. INC. (MRK) Stock Institutional Trading Activity


MERCK & CO. INC. (MRK) position changes reported by tracked institutional filers across multiple SEC 13F reporting periods. Based on recent SEC 13F filings (Q4 2025), investors with some of the largest reported share count changes include Causeway Capital Management, Cullen Value Fund, Kahn Brothers Group, Matrix Private Capital Group, and Mairs & Power Growth Fund. Explore insights into buying and selling patterns, position changes, and investment conviction levels to understand institutional trading behavior and market dynamics.

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Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q4 2020Sound Shore ManagementBuy299,7901,348,746$110,327
Q4 2020Matrix Private Capital GroupSell-528,162$673
Q4 2020Renaissance Technologies LLCSell-1,195,52428,215$2,308
Q4 2020Sequoia Financial AdvisorsSell-8246,679$3,818
Q4 2020Hillman Value FundBuy20,41458,881$4,816
Q4 2020Mairs & Power Growth FundBuy2,65681,771$6,689
Q4 2020Matrix Advisors Value FundBuy7,550120,937$9,893
Q4 2020Fairfax Financial HoldingsBuy110,900122,900$10,053
Q4 2020Berkshire HathawayBuy6,294,33328,697,435$2,347,450
Q4 2020Gardner Russo & QuinnBuy93,944$323
Q3 2020Torray FundBuy4515,199$1,261
Q3 2020Dodge & Cox Stock FundSell-38,250307,729$25,526
Q3 2020Sound Shore ManagementSell-441,0551,048,956$87,011
Q3 2020Hillman Value FundSell-5138,467$3,191
Q3 2020Sequoia Financial AdvisorsBuy46,76146,761$3,879
Q3 2020Mairs & Power Growth FundSell-1,71579,115$6,563
Q3 2020Matrix Advisors Value FundSell-16,748113,387$9,405
Q3 2020Renaissance Technologies LLCSell-2,516,6901,223,739$101,509
Q3 2020Berkshire HathawayBuy22,403,10222,403,102$1,858,337
Q3 2020Gardner Russo & QuinnBuy93,935$326
Q2 2020Lountzis Asset ManagementBuy5757$4
Q2 2020Torray FundSell-1,57015,154$1,172
Q2 2020Dodge & Cox Stock FundSell-170,979345,979$26,755
Q2 2020Sound Shore ManagementSell-184,2861,490,011$115,223
Q2 2020Causeway Capital ManagementSell-640,968814,074$62,952
Q2 2020Matrix Private Capital GroupBuy2228,214$640
Q2 2020Sequoia Financial AdvisorsSell-32,8560$2,868
Q2 2020Hillman Value FundSell-438,518$2,979
Q2 2020Mairs & Power Growth FundSell-82480,830$6,251
Q2 2020Matrix Advisors Value FundBuy12,126130,135$10,063

Frequently asked questions about MRK activity

  • Which institutional owners are buying MRK?

    Institutional owners buying MRK include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in MRK activity?

    "Buy" means an investor increased their reported position in MRK compared to the prior reporting period. This reflects growing exposure to MERCK & CO. INC. (MRK) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in MRK increasing?

    Institutional interest in MRK can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.