Ken Griffin Merck & Co., Inc. Transaction History

Citadel Advisors LLC

$618 Billion
Q3 2025

A detailed history of Ken Griffin (Citadel Advisors LLC) transactions in Merck & Co., Inc. stock. As of the latest transaction made, Citadel Advisors LLC holds 5,917,500 shares of MRK stock, worth $549 Million. This represents 0.08% of its overall portfolio holdings.

Number of Shares

5,917,500

Previous 5,857,500 1.02%

Holding current value

$549 Million

Previous $464 Million 7.11%

% of portfolio

0.08%

Previous 0.08%

32 transactions

Quarter	Operation	Price Per share	shares change	shares Held
Q3 2025 Nov 14, 2025	BUY	$77.6 - $87.37 $75.1 Million - $84.6 Million	968,054 New	968,054 $81.2 Million
Q1 2025 May 15, 2025	SELL	$83.01 - $101.02 $268 Million - $327 Million	-3,232,971 Reduced 61.21%	2,048,739 $184 Million
Q4 2024 Feb 14, 2025	SELL	$96.31 - $114.76 $170 Million - $202 Million	-1,759,979 Reduced 24.99%	5,281,710 $525 Million
Q3 2024 Nov 14, 2024	SELL	$111.15 - $128.97 $133 Million - $155 Million	-1,200,378 Reduced 14.56%	7,041,689 $800 Million
Q2 2024 Aug 14, 2024	BUY	$123.8 - $132.96 $82.6 Million - $88.7 Million	666,847 Added 8.8%	8,242,067 $1.02 Billion

Q1 2024 May 15, 2024	BUY	$113.24 - $131.95 $142 Million - $166 Million	1,257,049 Added 19.9%	7,575,220 $1 Billion
Q4 2023 Feb 14, 2024	SELL	$100.18 - $109.02 $36 Million - $39.1 Million	-358,936 Reduced 5.38%	6,318,171 $689 Million
Q3 2023 Nov 14, 2023	BUY	$102.95 - $114.33 $498 Million - $553 Million	4,837,236 Added 262.91%	6,677,107 $687 Million
Q2 2023 Aug 14, 2023	BUY	$108.61 - $118.38 $116 Million - $127 Million	1,068,727 Added 138.59%	1,839,871 $212 Million
Q1 2023 May 15, 2023	SELL	$102.94 - $114.86 $177 Million - $197 Million	-1,715,524 Reduced 68.99%	771,144 $82 Million
Q4 2022 Feb 14, 2023	SELL	$87.44 - $112.11 $78.7 Million - $101 Million	-900,548 Reduced 26.59%	2,486,668 $276 Million
Q3 2022 Nov 14, 2022	BUY	$84.53 - $94.96 $104 Million - $117 Million	1,231,726 Added 57.14%	3,387,216 $292 Million
Q2 2022 Aug 15, 2022	SELL	$83.49 - $94.64 $103 Million - $117 Million	-1,233,115 Reduced 36.39%	2,155,490 $197 Million
Q1 2022 May 16, 2022	BUY	$73.51 - $82.4 $86.1 Million - $96.5 Million	1,171,399 Added 52.83%	3,388,605 $278 Million
Q4 2021 Feb 14, 2022	SELL	$72.28 - $90.54 $63 Million - $78.9 Million	-871,326 Reduced 28.21%	2,217,206 $170 Million
Q3 2021 Nov 15, 2021	BUY	$71.68 - $78.83 $9.92 Million - $10.9 Million	138,422 Added 4.69%	3,088,532 $232 Million
Q2 2021 Aug 16, 2021	SELL	$70.31 - $77.77 $101 Million - $111 Million	-1,431,650 Reduced 32.67%	2,950,110 $229 Million
Q1 2021 May 17, 2021	SELL	$68.86 - $81.11 $38.5 Million - $45.4 Million	-559,774 Reduced 11.33%	4,381,760 $338 Million
Q4 2020 Feb 16, 2021	BUY	$71.77 - $79.65 $203 Million - $226 Million	2,833,384 Added 134.4%	4,941,534 $404 Million
Q3 2020 Nov 16, 2020	BUY	$73.18 - $82.95 $56.8 Million - $64.4 Million	776,626 Added 58.33%	2,108,150 $175 Million
Q2 2020 Aug 14, 2020	SELL	$70.42 - $80.13 $7.2 Million - $8.19 Million	-102,236 Reduced 7.13%	1,331,524 $103 Million
Q1 2020 May 15, 2020	BUY	$63.36 - $87.82 $31.5 Million - $43.6 Million	496,742 Added 53.01%	1,433,760 $110 Million
Q4 2019 Feb 14, 2020	SELL	$77.58 - $87.54 $132 Million - $149 Million	-1,707,170 Reduced 64.56%	937,018 $85.2 Million
Q3 2019 Nov 14, 2019	BUY	$76.08 - $82.93 $148 Million - $162 Million	1,950,861 Added 281.38%	2,644,188 $212 Million
Q2 2019 Aug 14, 2019	SELL	$69.84 - $81.59 $40.3 Million - $47.1 Million	-577,166 Reduced 45.43%	693,327 $58.1 Million
Q1 2019 May 15, 2019	SELL	$69.58 - $79.36 $39.2 Million - $44.7 Million	-563,408 Reduced 30.72%	1,270,493 $0
Q4 2018 Feb 14, 2019	SELL	$65.24 - $75.71 $217 Million - $252 Million	-3,331,026 Reduced 64.49%	1,833,901 $134 Million
Q3 2018 Nov 13, 2018	BUY	$57.69 - $67.84 $111 Million - $131 Million	1,926,113 Added 59.47%	5,164,927 $0
Q2 2018 Aug 10, 2018	SELL	$50.83 - $59.72 $144 Million - $169 Million	-2,825,198 Reduced 46.59%	3,238,814 $0
Q1 2018 May 11, 2018	SELL	$50.96 - $59.23 $120 Million - $140 Million	-2,364,413 Reduced 28.05%	6,064,012 $330 Million
Q4 2017 Feb 09, 2018	BUY	$51.62 - $61.64 $402 Million - $480 Million	7,792,358 Added 1225.08%	8,428,425 $474 Million
Q3 2017 Nov 09, 2017	BUY	$58.67 - $63.13 $37.3 Million - $40.2 Million	636,067	636,067 $40.7 Million

Others Institutions Holding MRK

# of Institutions

3,875

Shares Held

1.9B

Call Options Held

30.1M

Put Options Held

27.7M

View Full List

About Merck & Co., Inc.

Ticker MRK
Exchange NYSE
Sector Healthcare
Industry Drug Manufacturers—General
Shares Outstandng 2,533,280,000
Market Cap $235B
Description
Merck & Co., Inc. operates as a healthcare company worldwide. It operates through two segments, Pharmaceutical and Animal Health. The Pharmaceutical segment offers human health pharmaceutical products in the areas of oncology, hospital acute care, immunology, neuroscience, virology, cardiovascular, and diabetes, as well as vaccine products, ...

More about MRK

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