Vanguard Group Inc ownership in 6MK / Merck & Co., Inc.

Merck & Co., Inc.

BG ˙ BUL ˙ US58933Y1055

Security	BG:6MK / Merck & Co., Inc.
Institution	Vanguard Group Inc
Latest Disclosed Ownership	253,257,639 shares
Ownership	10.02%

2025-03-06 - Vanguard Group Inc has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 253,257,639 shares of Merck & Co., Inc. (BG:6MK). This represents 10.02 percent ownership of the company. In their previous filing dated 2024-02-13 , Vanguard Group Inc had reported owning 244,767,034 shares, indicating an increase of 3.47 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File Date	Effective Date	Form	Prev Shares	Latest Shares	ΔShares (Percent)	Ownership (Percent)	ΔOwnership (Percent)
2025-03-06	2025-03-06	13G/A	244,767,034	253,257,639	3.47	10.02	3.73
2024-02-13	2024-02-13	13G/A	227,205,978	244,767,034	7.73	9.66	7.81
2023-02-09	2023-02-09	13G/A	211,202,531	227,205,978	7.58	8.96	7.18
2022-02-09	2022-02-09	13G/A	208,410,644	211,202,531	1.34	8.36	1.46
2021-02-10	2021-02-10	13G/A	210,542,333	208,410,644	-1.01	8.24	-0.24
2020-02-12	2020-02-12	13G/A	205,593,589	210,542,333	2.41	8.26	4.56
2019-02-11	2019-02-11	13G/A	197,466,971	205,593,589	4.12	7.90	9.12
2018-02-09	2018-02-09	13G/A	184,729,642	197,466,971	6.90	7.24	8.06
2017-02-10	2017-02-10	13G/A	167,627,208	184,729,642	10.20	6.70	11.67
2016-02-10	2016-02-10	13G/A		167,627,208		6.00
2015-02-11	2015-02-11	13G		155,705,154		5.46

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)

File Date	Effective Date	Form	Security	Class	ID	Reported Shares	ΔShares	ΔShares (%)	Reported Value (x1000)	ΔValue (%)	Alloc (%)
2026-01-29	2025-12-31	13F	MERCK	COM	58933Y105	254,322,763	2,185,853	0.87	26,770,014	26.50	0.3881
2025-11-07	2025-09-30	13F	MERCK	COM	58933Y105	252,136,910	-777,516	-0.31	21,161,851	5.70	0.3168
2025-08-11	2025-06-30	13F	MERCK	COM	58933Y105	252,914,426	401,045	0.16	20,020,706	-11.67	0.3241
2025-05-09	2025-03-31	13F	MERCK	COM	58933Y105	252,513,381	1,417,274	0.56	22,665,601	-9.26	0.4098
2025-02-11	2024-12-31	13F	MERCK	COM	58933Y105	251,096,107	1,292,192	0.52	24,979,041	-11.95	0.4351
2024-11-13	2024-09-30	13F	MERCK	COM	58933Y105	249,803,915	5,126,701	2.10	28,367,733	-6.35	0.5080
2024-08-13	2024-06-30	13F	MERCK	COM	58933Y105	244,677,214	1,407,315	0.58	30,291,039	-5.63	0.5819
2024-05-10	2024-03-31	13F	MERCK	COM	58933Y105	243,269,899	-1,506,848	-0.62	32,099,463	20.29	0.6358
2024-03-11	2023-12-31	13F/A-1	MERCK	COM	58933Y105	244,776,747	1,236,228	0.51	26,685,561	6.43	0.5830
2024-02-14	2023-12-31	13F	MERCK	COM	58933Y105	244,776,747	1,236,228		26,685,561		0.5840
2023-12-18	2023-09-30	13F/A-1	MERCK	COM	58933Y105	243,540,519	-99,634	-0.04	25,072,496	-10.82	0.6159
2023-11-14	2023-09-30	13F	MERCK	COM	58933Y105	243,540,519	-99,634		25,072,496		0.6159
2023-08-14	2023-06-30	13F	MERCK	COM	58933Y105	243,640,153	-304,970	-0.13	28,113,637	8.32	0.6666
2023-07-14	2023-03-31	13F/A-1	MERCK	COM	58933Y105	243,945,123	16,739,145	7.37	25,953,322	2.95	0.6608
2023-05-15	2023-03-31	13F	MERCK	COM	58933Y105	243,936,873	16,730,895		25,952,444		0.6610
2023-02-10	2022-12-31	13F	MERCK	COM	58933Y105	227,205,978	3,071,530	1.37	25,208,503	30.60	0.6864
2022-11-14	2022-09-30	13F	MERCK	COM	58933Y105	224,134,448	3,081,402	1.39	19,302,459	-4.22	0.5677
2022-08-12	2022-06-30	13F	MERCK	COM	58933Y105	221,053,046	4,956,989	2.29	20,153,406	13.66	0.5665
2022-05-13	2022-03-31	13F	MERCK	COM	58933Y105	216,096,057	4,893,526	2.32	17,730,682	9.54	0.4194
2022-02-14	2021-12-31	13F	MERCK	COM	58933Y105	211,202,531	734,443	0.35	16,186,562	2.39	0.3675
2021-11-12	2021-09-30	13F	MERCK	COM	58933Y105	210,468,088	-15,085,702	-6.69	15,808,258	-9.88	0.3926
2021-08-13	2021-06-30	13F	MERCK	COM	58933Y105	225,553,790	347,861	0.15	17,541,317	1.04	0.4365
2021-05-14	2021-03-31	13F	MERCK & CO.	COM	58933Y105	225,205,929	16,795,285	8.06	17,361,125	1.84	0.4696
2021-02-12	2020-12-31	13F	MERCK & CO.	COM	58933Y105	208,410,644	-1,455,280	-0.69	17,047,990	-2.07	0.4945
2020-11-16	2020-09-30	13F	MERCK & CO.	COM	58933Y105	209,865,924	-2,918,763	-1.37	17,408,377	5.80	0.5761
2020-08-14	2020-06-30	13F	MERCK & CO.	COM	58933Y105	212,784,687	-4,210,785	-1.94	16,454,640	-1.44	0.5836
2020-05-15	2020-03-31	13F	MERCK & CO.	COM	58933Y105	216,995,472	6,453,139	3.07	16,695,632	-12.81	0.7115
2020-02-14	2019-12-31	13F	MERCK	COM	58933Y105	210,542,333	1,046,896	0.50	19,148,826	8.58	0.6530
2019-11-14	2019-09-30	13F	MERCK	COM	58933Y105	209,495,437	-10,338	-0.00	17,635,326	0.39	0.6540
2019-08-14	2019-06-30	13F	MERCK	COM	58933Y105	209,505,775	1,694,360	0.82	17,567,058	1.64	0.6609
2019-05-15	2019-03-31	13F	MERCK	COM	58933Y105	207,811,415	2,217,826	1.08	17,283,675	10.02	0.6780
2019-02-14	2018-12-31	13F	MERCK	COM	58933Y105	205,593,589	2,759,591	1.36	15,709,407	9.18	0.7058
2018-12-13	2018-09-30	13F/A-2	MERCK	COM	58933Y105	202,833,998	924,701	0.46	14,389,044	17.41	0.5623
2018-11-23	2018-09-30	13F/A-1	MERCK	COM	58933Y105	202,833,998	0		14,389,044		0.5623
2018-11-14	2018-09-30	13F	MERCK	COM	58933Y105	202,833,998	924,701		14,389,044
2018-08-14	2018-06-30	13F	MERCK	COM	58933Y105	201,909,297	2,906,059	1.46	12,255,894	13.06	0.5127
2018-05-15	2018-03-31	13F	MERCK	COM	58933Y105	199,003,238	1,536,267	0.78	10,839,706	-2.45	0.4740
2018-02-14	2017-12-31	13F	MERCK	COM	58933Y105	197,466,971	394,191	0.20	11,111,466	-11.94	0.4859
2017-11-14	2017-09-30	13F	MERCK	COM	58933Y105	197,072,780	2,928,463	1.51	12,618,570	1.41	0.5898
2017-08-24	2017-06-30	13F/A-1	MERCK	COM	58933Y105	194,144,317	3,312,459	1.74	12,442,709	2.62	0.6128
2017-08-11	2017-06-30	13F	MERCK	COM	58933Y105	194,144,317	3,312,459		12,442,709
2017-05-12	2017-03-31	13F	MERCK	COM	58933Y105	190,831,858	6,102,216	3.30	12,125,457	11.50	0.6234
2017-02-14	2016-12-31	13F	MERCK	COM	58933Y105	184,729,642	4,748,375	2.64	10,875,035	-3.18	0.6067
2016-11-14	2016-09-30	13F	MERCK	COM	58933Y105	179,981,267	5,161,573	2.95	11,232,630	11.53	0.6598
2016-08-10	2016-06-30	13F	MERCK	COM	58933Y105	174,819,694	3,242,254	1.89	10,071,362	10.94	0.6255
2016-05-13	2016-03-31	13F	MERCK & CO INC	COM	58933Y105	171,577,440	3,950,232	2.36	9,078,163	2.53	0.5882
2016-02-08	2015-12-31	13F	MERCK & CO INC	COM	58933Y105	167,627,208	2,353,965	1.42	8,854,069	8.47	0.5953
2015-11-12	2015-09-30	13F/A-1	MERCK & CO INC	COM	58933Y105	165,273,243	1,347,738	0.82	8,162,844	-12.53	0.3466
2015-11-12	2015-09-30	13F/A-1	MERCK & CO INC	COM	58933Y105	165,273,243	1,347,738		8,162,844		0.3466
2015-08-13	2015-06-30	13F	MERCK & CO INC	COM	58933Y105	163,925,505	1,365,691	0.84	9,332,279	-0.12	0.6308
2015-05-15	2015-03-31	13F/A-1	MERCK & CO INC	COM	58933Y105	162,559,814	6,854,660	4.40	9,343,938	5.67	0.6337
2015-05-14	2015-03-31	13F	MERCK & CO INC	COM	58933Y105	162,559,814			9,343,938
2015-02-12	2014-12-31	13F	MERCK & CO INC	COM	58933Y105	155,705,154	2,456,064	1.60	8,842,495	-2.67	0.6368
2014-11-12	2014-09-30	13F	MERCK & CO INC	COM	58933Y105	153,249,090	2,618,226	1.74	9,084,606	4.25	0.7082
2014-08-11	2014-06-30	13F	MERCK & CO INC	COM	58933Y105	150,630,864	2,649,076	1.79	8,713,995	3.73	0.6866
2014-05-13	2014-03-31	13F	MERCK & CO INC	COM	58933Y105	147,981,788	4,575,944	3.19	8,400,926	17.05	0.7066
2014-02-12	2013-12-31	13F	MERCK & CO INC	COM	58933Y105	143,405,844	2,041,593	1.44	7,177,463	6.64	0.6312
2013-11-07	2013-09-30	13F	MERCK & CO INC	COM	58933Y105	141,364,251	-1,576,036	-1.10	6,730,353	1.37	0.6573
2013-08-13	2013-06-30	13F	MERCK & CO INC	COM	58933Y105	142,940,287	142,940,287		6,639,576		0.6973

Legend

Shares: The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value: The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price: The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class: This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred

Allocation (%): The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation: The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%): The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis: The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss: This is the market value of the position as of the effective date minus the cost basis.