MRK insider ownership: who sold, why, and what they still hold

Who	Shares	Price	% of total stake	Total stake after	Trade date	Filed
Chirfi Guindo EVP, Access, Policy & Comms	10,000	$135.00	22%	35K	Aug 13, 2026	Aug 13, 2026

What stands out

Four officers sold more than 25% of vested holdings: Richard DeLuca (49% of holdings, $11.3M, none under a disclosed plan), Chirfi Guindo (73% of holdings, $8.2M, none under a disclosed plan) and Dean Li (32% of holdings, $3.0M, none under a disclosed plan), plus 1 more.Richard DeLuca: largest sale, Feb 6, 2026 · Chirfi Guindo: largest sale, Feb 5, 2026 · Dean Li: largest sale, Feb 4, 2026

Five officers sold $46.4M with no disclosed plan: Jennifer Zachary ($25.2M), David Williams ($8.1M) and Robert Davis ($5.6M, 11% of holdings), plus 2 more. The filings don't state a reason.Jennifer Zachary: largest such sale, Aug 12, 2026 · David Williams: largest such sale, Aug 5, 2026 · Robert Davis: largest such sale, Feb 4, 2026

Robert Davis sold 47K shares (11% of starting holdings), but 61K more vested, so the stake grew (from 444K to 450K).Largest sale, Feb 4, 2026

Percentages cover 20 of 28 officers and directors. 8 are left out

Left out: Sanat Chattopadhyay and Jennifer Zachary (holdings couldn't be fully reconciled); Caroline Litchfield, David Williams, David Maraldo and Dalton Smart III (most of their shares vested during the period, so a percentage would mislead); Patricia Russo (most holdings were last confirmed in 2006); Brian Foard (held no vested shares at the start).

Disclosed company stock is not an insider's whole wealth.

Who sold, and how much of their stake

Officers and directors, past 12 months. Each bar is 100% of that person's own stake; not comparable between people. The stake is the vested shares held at the start of the period (Oct 9, 2025); the gold part is what they sold.

SoldRest of starting stakeAdded during the period

Jennifer Zachary

EVP, General Counsel

Sold $25.2M (plan status beside the amount). Share of stake not shown: holdings couldn't be fully reconciled. Why

$25.2MNo plan disclosed

Richard DeLuca

EVP&Pres, Merck Animal Heallth

49% · $11.3MNo plan disclosed

Chirfi Guindo

EVP, Access, Policy & Comms

73% · $8.2MNo plan disclosed

David Williams

EVP,Chief Info&Digital Officer

Sold $8.1M (plan status beside the amount). That is 68% of the shares held or received (after tax withholding) during the period†. A share of the starting stake is not shown: most of these shares arrived during the period. Why

$8.1MNo plan disclosed

Robert Davis

Chairman, CEO & President, Director

Sold 11%, but 13K shares were added (mostly vesting), so the stake grew

11% · $5.6MNo plan disclosed

All 11 sellers

Selling by month

Officers and directors, Oct 2025 to Oct 2026. Each sale is counted once: under a disclosed plan, else to cover taxes, else no plan disclosed.

No plan disclosedOne dollar scale for every month; the tallest bar is labeled

Common questions

Is the Merck & Co. CEO selling stock?

Yes. Robert Davis sold 47K shares ($5.6M, 11% of starting holdings) in the past 12 months, none of it under a trading plan disclosed in the filings.

Why are Merck & Co. insiders selling?

Filings rarely give a reason, and we don't guess at one. What they show is how the sales were made: 0% of sales by value ran under 10b5-1 trading plans disclosed in the filings and 100% had no disclosed plan. A trading plan schedules sales in advance.

Are any Merck & Co. insiders buying?

No. Officers and directors reported no purchases in the past 12 months.

How much of their stake did Merck & Co. insiders sell?

About 28% overall. As a group they still hold 88% of their starting shares. These figures leave out Sanat Chattopadhyay, the largest holder (holdings couldn't be fully reconciled). That covers the 12 months to Oct 9, 2026 and counts vested shares reported on SEC Forms 3, 4 and 5, which is not an insider's whole wealth.

The evidence

Who sold11 officers and directors: amount, % of holdings, trading plan

Who sold	Amount	% of holdings	Trading plan
Jennifer Zachary EVP, General Counsel	$25.2M 202K shares	i No percentage: holdings couldn't be fully reconciled.	No plan disclosed
Richard DeLuca EVP&Pres, Merck Animal Heallth	$11.3M 89K shares	49%	No plan disclosed
Chirfi Guindo EVP, Access, Policy & Comms	$8.2M 65K shares	73%	No plan disclosed
David Williams EVP,Chief Info&Digital Officer	$8.1M 66K shares	68%† i † Most of the shares David Williams sold arrived during the period, so this is shares sold as a share of the 33K held at the start plus the 65K received, less 679 withheld by the company for taxes.	No plan disclosed
Robert Davis Chairman, CEO & President, Director	$5.6M 47K shares	11%	No plan disclosed
Caroline Litchfield EVP & CFO	$5.0M 42K shares	31%† i † Most of the shares Caroline Litchfield sold arrived during the period, so this is shares sold as a share of the 74K held at the start plus the 62K received, less 1.9K withheld by the company for taxes.	No plan disclosed
Dean Li Executive VP & President, MRL	$3.0M 25K shares	32%	No plan disclosed
David Maraldo EVP & Pres. MMD	$2.4M 19K shares	41%† i † Most of the shares David Maraldo sold arrived during the period, so this is shares sold as a share of the 26K held at the start plus the 19K received, less 159 withheld by the company for taxes.	No plan disclosed
Johannes Oosthuizen EVP, Oncology & Int?l	$1.8M 15K shares	49%	No plan disclosed
Dalton Smart III SVP Fin. - Global Controller	$766K 6.4K shares	41%† i † Most of the shares Dalton Smart III sold arrived during the period, so this is shares sold as a share of the 9.5K held at the start plus the 6.9K received, less 615 withheld by the company for taxes.	No plan disclosed
Cristal Downing Chief Comm. & Public Afrs Ofcr	$616K 7.1K shares	100%	No plan disclosed

The full ownership picture26 of 28 insiders fully reconciled · 27 officers and directors

Vested shares across all share classes, held directly and through trusts, LLCs and family members, as reported on SEC Forms 3, 4 and 5. Unvested awards and options are never counted as owned shares.

Insider

Held Oct 9, 2025

Sold

Held Oct 9, 2026

Still held

Robert Davis

Chairman, CEO & President, Director

444K

−47K

450K

+1.5%

Vesting, gifts, unvested awards and holding lines for Robert Davis

+13Kshares vested or exercised

0gifted (net of own trusts)

−6.6Kwithheld by the company for taxes

40K → 74Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	443,602	450,351

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
83,020	$75.36	Apr 30, 2030	$5.0M
96,760	$73.73	May 3, 2031	$5.9M
181,641	$129.22	Apr 29, 2034	$1.0M
181,623	$84.71	Apr 28, 2035	$9.1M
139,697	$113.15	May 4, 2036	$3.1M

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Sanat Chattopadhyay

Holdings couldn't be fully reconciled. Filings report each grant's shares as the balance instead of a running total. See the filing Sales and other transactions for Sanat Chattopadhyay are complete.

Exe V-P & Pres. MMD

n/a

Vesting, gifts, unvested awards and holding lines for Sanat Chattopadhyay

+2.6Kshares vested or exercised

0gifted (net of own trusts)

−1.1Kwithheld by the company for taxes

7.8K → 5.2Kunvested awards, start → end

Additional holdings last reported more than 3 years ago are shown separately and excluded from totals.

Holdings couldn't be fully reconciled. Filings report each grant's shares as the balance instead of a running total. The balances below are as reported, not verified totals.

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	78,758	15,347
GRAT April 2025	Common Stock	74,289	74,289
GRAT February 2025	Common Stock	53,417	53,417
GRAT May 2024	Common Stock	50,622	50,622
GRAT 2023	Common Stock	46,995	46,995
GRAT 2021	Common Stock	37,873	37,873
GRAT 2024	Common Stock	33,000	33,000
GRAT 2022	Common Stock	26,575	26,575
GRAT February 2024	Common Stock	7,000	7,000
GRAT August 2025	Common Stock	0	57,622

Additional holdings last reported Oct 28, 2022, not confirmed since: 67,373 shares. Not included in any total or percentage on this page.

GRAT, Common Stock: 67,373 shares, last reported Oct 28, 2022

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
38,672	$129.22	Apr 29, 2034	$224K
35,465	$84.71	Apr 28, 2035	$1.8M

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Richard DeLuca

Minor difference of 4,991 shares. Small increase from a 401(k) plan and dividend reinvestment. Small increase from a 401(k) plan and dividend reinvestment.

EVP&Pres, Merck Animal Heallth

182K

−89K

111K

61%

Vesting, gifts, unvested awards and holding lines for Richard DeLuca

+2.5Kshares vested or exercised

0gifted (net of own trusts)

−1.2Kwithheld by the company for taxes

31K → 40Kunvested awards, start → end

Small increase from a 401(k) plan and dividend reinvestment. Filing 1 Filing 2

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	180,730	110,167
401(k)	Common Stock - 401(k) Plan	1,281	1,321

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
37,500	$129.22	Apr 29, 2034	$217K
34,390	$84.71	Apr 28, 2035	$1.7M
34,924	$113.15	May 4, 2036	$763K

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Reconciliation: minor difference of 4,991 shares. Small increase from a 401(k) plan and dividend reinvestment.

Chirfi Guindo

Minor difference of 1,517 shares. Small increase from a 401(k) plan and dividend reinvestment. Small increase from a 401(k) plan and dividend reinvestment.

EVP, Access, Policy & Comms

89K

−65K

37K

41%

Vesting, gifts, unvested awards and holding lines for Chirfi Guindo

+2Kshares vested or exercised

0gifted (net of own trusts)

−969withheld by the company for taxes

5.9K → 11Kunvested awards, start → end

Small increase from a 401(k) plan and dividend reinvestment. Filing

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	89,234	36,613
401(k)	Common Stock-401(k) Plan	56	57

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
29,297	$129.22	Apr 29, 2034	$169K
26,867	$84.71	Apr 28, 2035	$1.4M
19,402	$113.15	May 4, 2036	$424K

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Reconciliation: minor difference of 1,517 shares. Small increase from a 401(k) plan and dividend reinvestment.

Dean Li

Minor difference of 1,620 shares. Small increase from dividend reinvestment. Small increase from dividend reinvestment.

Executive VP & President, MRL

80K

−25K

94K

+18%

Vesting, gifts, unvested awards and holding lines for Dean Li

+20Kshares vested or exercised

0gifted (net of own trusts)

−2.3Kwithheld by the company for taxes

14K → 29Kunvested awards, start → end

Small increase from dividend reinvestment. Filing

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	80,181	94,431

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
65,625	$129.22	Apr 29, 2034	$379K
64,481	$84.71	Apr 28, 2035	$3.2M
58,207	$113.15	May 4, 2036	$1.3M

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Reconciliation: minor difference of 1,620 shares. Small increase from dividend reinvestment.

Caroline Litchfield

Minor difference of 111 shares. Difference is under 0.5% of holdings.

EVP & CFO

74K

−42K

92K

not meaningful

Vesting, gifts, unvested awards and holding lines for Caroline Litchfield

+46Kshares vested or exercised

0gifted (net of own trusts)

−1.9Kwithheld by the company for taxes

12K → 24Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	74,340	92,301

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
49,805	$129.22	Apr 29, 2034	$288K
53,735	$84.71	Apr 28, 2035	$2.7M
46,566	$113.15	May 4, 2036	$1.0M

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Reconciliation: minor difference of 111 shares. Difference is under 0.5% of holdings.

Jennifer Zachary

Holdings couldn't be fully reconciled. A footnote describes a transfer or distribution between related entities, but the amounts could not be matched to the balance change. Largest: +1,501.49 shares on Jan 26, 2026 (Direct). See the filing Sales and other transactions for Jennifer Zachary are complete.

EVP, General Counsel

n/a

−202K

n/a

Vesting, gifts, unvested awards and holding lines for Jennifer Zachary

+179Kshares vested or exercised

0gifted (net of own trusts)

−1.5Kwithheld by the company for taxes

8.9K → 18Kunvested awards, start → end

Holdings couldn't be fully reconciled. A footnote describes a transfer or distribution between related entities, but the amounts could not be matched to the balance change. Largest: +1,501.49 shares on Jan 26, 2026 (Direct). The balances below are as reported, not verified totals.

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	55,831	45,509

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
35,156	$129.22	Apr 29, 2034	$203K
40,301	$84.71	Apr 28, 2035	$2.0M
35,312	$113.15	May 4, 2036	$772K

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

David Williams

Minor difference of 507 shares. Small increase from dividend reinvestment. Small increase from dividend reinvestment.

EVP,Chief Info&Digital Officer

33K

−66K

32K

not meaningful

Vesting, gifts, unvested awards and holding lines for David Williams

+59Kshares vested or exercised

0gifted (net of own trusts)

−679withheld by the company for taxes

4.1K → 7.4Kunvested awards, start → end

Small increase from dividend reinvestment. Filing 1 Filing 2 Filing 3

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	33,013	31,716

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
16,406	$129.22	Apr 29, 2034	$95K
18,807	$84.71	Apr 28, 2035	$946K
13,582	$113.15	May 4, 2036	$297K

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Reconciliation: minor difference of 507 shares. Small increase from dividend reinvestment.

Johannes Oosthuizen

Minor difference of 342 shares. Small increase from dividend reinvestment. Small increase from dividend reinvestment.

EVP, Oncology & Int?l

31K

−15K

22K

71%

Vesting, gifts, unvested awards and holding lines for Johannes Oosthuizen

+1.4Kshares vested or exercised

0gifted (net of own trusts)

−679withheld by the company for taxes

4.1K → 13Kunvested awards, start → end

Small increase from dividend reinvestment. Filing

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	30,830	21,895

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
7,049	$73.73	May 3, 2031	$432K
14,240	$87.10	May 2, 2032	$682K
20,508	$129.22	Apr 29, 2034	$119K
18,807	$84.71	Apr 28, 2035	$946K
31,044	$113.15	May 4, 2036	$678K

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Reconciliation: minor difference of 342 shares. Small increase from dividend reinvestment.

David Maraldo

Started reporting during the period; starting holdings are from the Form 3.

EVP & Pres. MMD

26K

−19K

27K

not meaningful

Vesting, gifts, unvested awards and holding lines for David Maraldo

+19Kshares vested or exercised

0gifted (net of own trusts)

−159withheld by the company for taxes

3.5K → 10Kunvested awards, start → end

Started reporting during the period; starting holdings are from the Form 3.

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	17,819	18,212
401 (k)	Common Stock - 401(k) Plan	8,359	8,359

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
3,154	$73.73	May 3, 2031	$193K
8,990	$117.89	May 1, 2033	$154K
8,789	$129.22	Apr 29, 2034	$51K
5,374	$84.71	Apr 28, 2035	$270K
21,731	$113.15	May 4, 2036	$475K

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Joseph Romanelli

Minor difference of 91 shares. Difference is under 0.5% of holdings.

President, Human Health Int?l

23K

29K

no sales

Vesting, gifts, unvested awards and holding lines for Joseph Romanelli

0shares vested or exercised

0gifted (net of own trusts)

21K → 21Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	22,946	28,739

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
23,438	$129.22	Apr 29, 2034	$135K
21,494	$84.71	Apr 28, 2035	$1.1M

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Reconciliation: minor difference of 91 shares. Difference is under 0.5% of holdings.

Douglas Baker Jr.

Director

16K

no sales

Vesting, gifts, unvested awards and holding lines for Douglas Baker Jr.

0shares vested or exercised

0gifted (net of own trusts)

16K → 27Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	16,000	16,000

Patricia Russo

Most of this insider's holdings were last confirmed in 2006. Confirmed in the last three years: 13,148 shares. Not confirmed since: 53,714 shares, left out of this row. "Still held" is not shown because it would cover only the smaller, confirmed part.

Director

13K

see note

Vesting, gifts, unvested awards and holding lines for Patricia Russo

0shares vested or exercised

0gifted (net of own trusts)

112K → 175Kunvested awards, start → end

Additional holdings last reported more than 3 years ago are shown separately and excluded from totals.

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	13,148	13,148

Additional holdings last reported Apr 1, 2006, not confirmed since: 53,714 shares. Not included in any total or percentage on this page.

Direct, Common Shares: 22,800 shares, last reported Apr 28, 2004
Direct, Stock Equivalent Units: 30,914 shares, last reported Apr 1, 2006

Dalton Smart III

Minor difference of 8 shares. Difference is under 0.5% of holdings.

SVP Fin. - Global Controller

9.5K

−6.4K

9.4K

not meaningful

Vesting, gifts, unvested awards and holding lines for Dalton Smart III

+5.8Kshares vested or exercised

0gifted (net of own trusts)

−615withheld by the company for taxes

4.1K → 4.7Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	9,539	9,388

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
8,130	$62.07	May 4, 2027	$593K
12,447	$56.04	May 3, 2028	$983K
9,600	$77.62	May 2, 2029	$551K
13,542	$75.36	Apr 30, 2030	$808K
14,198	$73.73	May 3, 2031	$870K
8,738	$87.10	May 2, 2032	$419K
6,224	$117.89	May 1, 2033	$106K
7,031	$129.22	Apr 29, 2034	$41K
6,448	$84.71	Apr 28, 2035	$324K
5,045	$113.15	May 4, 2036	$110K

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Reconciliation: minor difference of 8 shares. Difference is under 0.5% of holdings.

Cristal Downing

Chief Comm. & Public Afrs Ofcr

7.1K

−7.1K

Vesting, gifts, unvested awards and holding lines for Cristal Downing

0shares vested or exercised

0gifted (net of own trusts)

15K → 15Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	7,085	0

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
15,234	$129.22	Apr 29, 2034	$88K
13,971	$84.71	Apr 28, 2035	$703K

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Betty Larson

EVP, Chief HR Officer

6.2K

14K

no sales

Vesting, gifts, unvested awards and holding lines for Betty Larson

+13Kshares vested or exercised

0gifted (net of own trusts)

−5.9Kwithheld by the company for taxes

29K → 23Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	6,197	13,774

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
58,594	$129.22	Apr 29, 2034	$339K
31,055	$129.22	Apr 29, 2034	$179K
28,479	$84.71	Apr 28, 2035	$1.4M
23,283	$113.15	May 4, 2036	$509K

Estimate: options held × ($135.00 − strike price), using the most recent insider trade price on Form 4 (Aug 13, 2026), not a market close.

Thomas Glocer

Director

5.1K

no sales

Vesting, gifts, unvested awards and holding lines for Thomas Glocer

0shares vested or exercised

0gifted (net of own trusts)

786K → 1.11Munvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	5,100	5,100

Inge Thulin

Director

2.9K

no sales

Vesting, gifts, unvested awards and holding lines for Inge Thulin

0shares vested or exercised

0gifted (net of own trusts)

46K → 73Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	2,933	2,933

Pamela Craig

Director

1.7K

no sales

Vesting, gifts, unvested awards and holding lines for Pamela Craig

0shares vested or exercised

0gifted (net of own trusts)

60K → 95Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	1,715	1,715

Risa Lavizzo-Mourey

Director

no sales

Vesting, gifts, unvested awards and holding lines for Risa Lavizzo-Mourey

0shares vested or exercised

0gifted (net of own trusts)

27K → 45Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	1,000	1,000

Gaurav Gupta

Started reporting during the period; starting holdings are from the Form 3.

EVP, Cido

750

no sales

Vesting, gifts, unvested awards and holding lines for Gaurav Gupta

0shares vested or exercised

0gifted (net of own trusts)

19K → 19Kunvested awards, start → end

Started reporting during the period; starting holdings are from the Form 3.

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	750	750

Kathy Warden

Director

500

no sales

Vesting, gifts, unvested awards and holding lines for Kathy Warden

0shares vested or exercised

0gifted (net of own trusts)

28K → 46Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	500	500

Paul Rothman

Director

100

no sales

Vesting, gifts, unvested awards and holding lines for Paul Rothman

0shares vested or exercised

0gifted (net of own trusts)

60K → 95Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	100	100

Christine Seidman

Director

100

no sales

Vesting, gifts, unvested awards and holding lines for Christine Seidman

0shares vested or exercised

0gifted (net of own trusts)

123K → 204Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	100	100

Stephen Mayo

Director

100

no sales

Vesting, gifts, unvested awards and holding lines for Stephen Mayo

0shares vested or exercised

0gifted (net of own trusts)

22K → 37Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	100	100

Mary Coe

Director

no sales

Vesting, gifts, unvested awards and holding lines for Mary Coe

0shares vested or exercised

0gifted (net of own trusts)

194K → 317Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	10	10

Surendralal Karsanbhai

Director

no sales

Vesting, gifts, unvested awards and holding lines for Surendralal Karsanbhai

0shares vested or exercised

0gifted (net of own trusts)

4K → 15Kunvested awards, start → end

Held through	Share class	Oct 9, 2025	Oct 9, 2026
Direct	Common Stock	1	1

26 of 28 insiders fully reconciled: starting holdings plus reported transactions match ending holdings (18 exactly, 8 with a minor or footnoted difference). For 2 we show sales but not holdings; the ! icon on their rows explains why. Percentages cover 20 of 28 officers and directors. Left out: Sanat Chattopadhyay and Jennifer Zachary (holdings couldn't be fully reconciled); Caroline Litchfield, David Williams, David Maraldo and Dalton Smart III (most of their shares vested during the period, so a percentage would mislead); Patricia Russo (most holdings were last confirmed in 2006); Brian Foard (held no vested shares at the start). "Still held" compares ending with starting vested shares; a plus sign means the holding grew.

What explains the selling$72.0M of sales by plan status, purpose, seller and month

Officer and director open-market sales: $72.0M across 584,348 shares. Plan status and stated purpose are separate questions, and a sale can have both.

By plan status

No plan disclosed · $72.0M

Sales with no 10b5-1 plan and no tax reference in the filing. $25.2M of it is Jennifer Zachary. No plan disclosed is a statement about the filing, not about why the sale happened. Largest such sale: Jennifer Zachary, Aug 12, 2026

Taxes

23,599 shares ($2.6M) were withheld by the company for taxes, which isn't a market sale.

Seller	Shares sold	Proceeds	Under a disclosed plan	Share of total	Sales dates
Jennifer Zachary EVP, General Counsel	202K	$25.2M	0%	35%	Feb 9, 2026 to Aug 12, 2026
Richard DeLuca EVP&Pres, Merck Animal Heallth	89K	$11.3M	0%	16%	Feb 6, 2026 to Aug 12, 2026
Chirfi Guindo EVP, Access, Policy & Comms	65K	$8.2M	0%	11%	Feb 5, 2026 to Aug 13, 2026
David Williams EVP,Chief Info&Digital Officer	66K	$8.1M	0%	11%	Nov 3, 2025 to Aug 5, 2026
Robert Davis Chairman, CEO & President, Director	47K	$5.6M	0%	8%	Feb 4, 2026 to Feb 4, 2026
Caroline Litchfield EVP & CFO	42K	$5.0M	0%	7%	Feb 4, 2026 to Feb 4, 2026
Dean Li Executive VP & President, MRL	25K	$3.0M	0%	4%	Feb 4, 2026 to Feb 10, 2026
David Maraldo EVP & Pres. MMD	19K	$2.4M	0%	3%	Aug 5, 2026 to Aug 5, 2026
Johannes Oosthuizen EVP, Oncology & Int?l	15K	$1.8M	0%	3%	Feb 6, 2026 to Feb 6, 2026
Dalton Smart III SVP Fin. - Global Controller	6.4K	$766K	0%	1%	Feb 4, 2026 to Feb 4, 2026
Cristal Downing Chief Comm. & Public Afrs Ofcr	7.1K	$616K	0%	0.9%	Nov 10, 2025 to Nov 10, 2025

Sales by month

Month	Sale proceeds	Disclosed plan	To cover taxes	No plan disclosed
Oct 2025	$0	$0	$0	$0
Nov 2025	$1.3M	$0	$0	$1.3M
Dec 2025	$0	$0	$0	$0
Jan 2026	$0	$0	$0	$0
Feb 2026	$40.7M	$0	$0	$40.7M
Mar 2026	$0	$0	$0	$0
Apr 2026	$0	$0	$0	$0
May 2026	$0	$0	$0	$0
Jun 2026	$0	$0	$0	$0
Jul 2026	$0	$0	$0	$0
Aug 2026	$30.0M	$0	$0	$30.0M
Sep 2026	$0	$0	$0	$0
Oct 2026	$0	$0	$0	$0

Is this normal? Selling year by year5 earlier years to compare with

Less than usual: about half of the 5-year average. 11 insiders sold; the average is 6 a year.

12 months ending	Shares sold	Insiders who sold	Proceeds
Oct 9, 2026 Latest 12 months	584K	11	$72.0M
Oct 9, 2025 1 year earlier	21K	4	$1.8M
Oct 9, 2024 2 years earlier	456K	9	$56.4M
Oct 10, 2023 3 years earlier	3.61M	10	$371M
Oct 10, 2022 4 years earlier	1.03M	7	$87.1M
Oct 10, 2021 5 years earlier	299K	2	$24.3M

Open-market sales (Form 4 code S) by people who were officers or directors, in split-adjusted shares. Earlier years include people who have since left. A sale that an outside holder also reports (a family trust, a fund) is counted with outside holders in every year. Shares, not dollars, are compared, so a change in the stock price doesn't look like a change in selling. Years the filings don't fully cover are shown but left out of the average.

Known gaps and uncertainty2 insiders whose holdings couldn't be fully reconciled

Sanat Chattopadhyay: holdings couldn't be fully reconciled (difference of -21,136 shares). Filings report each grant's shares as the balance instead of a running total. Filing, Jan 26, 2026

Footnote: "Distribution of net after tax shares of common stock on satisfaction of performance criteria for performance share units granted on 3/31/23. Performance shares were paid out at 94 percent of target awards. Includes dividends accrued over the three-year performance period ending December 31, 2025."

Jennifer Zachary: holdings couldn't be fully reconciled (difference of 1,986 shares). A footnote describes a transfer or distribution between related entities, but the amounts could not be matched to the balance change. Largest: +1,501.49 shares on Jan 26, 2026 (Direct). Filing, Jan 26, 2026

Footnote: "Distribution of net after tax shares of common stock on satisfaction of performance criteria for performance share units granted on 3/31/23. Performance shares were paid out at 94 percent of target awards. Includes dividends accrued over the three-year performance period ending December 31, 2025. | Holdings include shares acquired in dividend reinvestment transactions."

Richard DeLuca: minor difference of 4,991 shares. Small increase from a 401(k) plan and dividend reinvestment.

Chirfi Guindo: minor difference of 1,517 shares. Small increase from a 401(k) plan and dividend reinvestment.

Dean Li: minor difference of 1,620 shares. Small increase from dividend reinvestment.

Caroline Litchfield: minor difference of 111 shares. Difference is under 0.5% of holdings.

David Williams: minor difference of 507 shares. Small increase from dividend reinvestment.

Johannes Oosthuizen: minor difference of 342 shares. Small increase from dividend reinvestment.

Joseph Romanelli: minor difference of 91 shares. Difference is under 0.5% of holdings.

Dalton Smart III: minor difference of 8 shares. Difference is under 0.5% of holdings.

External context: we only cite outside events when a documented connection exists. None is shown for this period.

Sources and methodology1,951 filings from SEC EDGAR, and how we read them

All 1,951 Forms 3, 4 and 5 filed for Merck & Co. (SEC CIK 310158) from Jun 25, 2003 to Oct 1, 2026, retrieved from SEC EDGAR on Oct 9, 2026. Prices are the ones reported in each filing, often weighted averages. 18 filings were left out because Merck & Co. filed them as an owner of another company's stock.

Holdings. Each holding line (a share class plus an owner, such as a trust or LLC) carries its last reported balance forward. Entities first reported during the period start at zero, so transfers between an insider's own trusts don't count as selling. Lines not reported for three years or more are listed separately and left out of totals.

Sales. A sale counts as under a 10b5-1 plan if its footnote cites one or the filing's Rule 10b5-1 box is checked, and as tax-related if its footnote cites tax obligations or sell-to-cover. Shares withheld by the company for taxes are listed separately. Sales with neither attribute are labeled "no plan disclosed".

Full methodology

Former or inactive filers (82)No filing in 18 months; last reported balances, not in any total

Name	Last filed	Last reported balance
Michael Klobuchar	May 6, 2024	25,198 shares, last reported balance as of May 4, 2024
Peter Wendell	Mar 29, 2024	1,000 shares, last reported balance as of Mar 28, 2024
Steven Mizell	Feb 2, 2024	23,619 shares, last reported balance as of Feb 2, 2024
Rita Karachun	May 5, 2023	45,710 shares, last reported balance as of May 4, 2023
Lisa LeCointe-Cephas	May 5, 2023	5,142 shares, last reported balance as of May 4, 2023
Kenneth Frazier	Nov 8, 2022	705,134 shares, last reported balance as of Nov 7, 2022
Arpa Garay	May 5, 2022	2,109 shares, last reported balance as of May 4, 2022
Julie Gerberding	Feb 28, 2022	48,712 shares, last reported balance as of Feb 24, 2022
Frank Clyburn	Nov 4, 2021	98,875 shares, last reported balance as of Nov 1, 2021
Leslie Brun	Jun 2, 2021	1,948 shares, last reported balance as of May 28, 2021
Michael Nally	Mar 2, 2021	21,390 shares, last reported balance as of Feb 26, 2021
Michael Fleming	Mar 2, 2021	10,283 shares, last reported balance as of Feb 26, 2021
Thomas Cech	Jun 2, 2020	100 shares, last reported balance as of May 29, 2020
Wendell Weeks	May 7, 2020	200 shares, last reported balance as of May 7, 2020
Roger Perlmutter	May 5, 2020	215,060 shares, last reported balance as of May 1, 2020
Rochelle Lazarus	Apr 2, 2020	6,881 shares, last reported balance as of Mar 31, 2020
James Scholefield	Nov 1, 2019	7,142 shares, last reported balance as of Oct 30, 2019
John Noseworthy	Apr 2, 2019	100 shares, last reported balance as of Mar 29, 2019
Adam Schechter	Nov 2, 2018	55,406 shares, last reported balance as of Nov 1, 2018
Ashley Watson	Nov 1, 2018	9,962 shares, last reported balance as of Oct 31, 2018
Craig Thompson	May 29, 2018	9,166 shares, last reported balance as of May 25, 2018
Weir Graddick	May 8, 2018	80,433 shares, last reported balance as of May 4, 2018
Michael Holston	Mar 1, 2018	69,786 shares, last reported balance as of Feb 27, 2018
Adele Ambrose	Sep 6, 2017	22,708 shares, last reported balance as of May 9, 2017
Carlos Represas	May 30, 2017	12,000 shares, last reported balance as of May 26, 2017
Robert Kidder	May 12, 2017	28,348 shares, last reported balance as of May 12, 2017
Clark Golestani	Aug 10, 2016	22,887 shares, last reported balance as of Aug 10, 2016
Michael Rosenblatt	May 12, 2016	41,473 shares, last reported balance as of May 10, 2016
William Harrison Jr.	Apr 13, 2016	16,400 shares, last reported balance as of Apr 13, 2016
Willie Deese	Feb 24, 2016	134,478 shares, last reported balance as of Feb 22, 2016
Bruce Kuhlik	May 5, 2015	150,432 shares, last reported balance as of May 4, 2015
Bridgette Heller	May 13, 2014	35,474 shares, last reported balance as of May 9, 2014
John Canan	Feb 26, 2014	16,956 shares, last reported balance as of Feb 24, 2014
Peter Kellogg	Feb 26, 2014	149,554 shares, last reported balance as of Feb 24, 2014
Cuong Do	May 8, 2013	No balance on record
Peter Kim	Feb 27, 2013	190,957 shares, last reported balance as of Feb 25, 2013
Richard Bowles III	May 10, 2012	77,545 shares, last reported balance as of May 10, 2012
Chris Scalet	May 4, 2012	83,041 shares, last reported balance as of May 2, 2012
Willam Kelley	Apr 3, 2012	4,311 shares, last reported balance as of Mar 30, 2012
Anne Tatlock	Apr 3, 2012	1,114 shares, last reported balance as of Mar 30, 2012
Steven Goldstone	Apr 3, 2012	2,000 shares, last reported balance as of Mar 30, 2012
Raul Kohan	Jan 4, 2012	139,187 shares, last reported balance as of Dec 31, 2011
Thomas Shenk	May 31, 2011	1,000 shares, last reported balance as of May 27, 2011
Harry Jacobson	May 31, 2011	4,034 shares, last reported balance as of May 27, 2011
Richard Clark	Mar 1, 2011	257,538 shares, last reported balance as of Feb 28, 2011
Mervyn Turner	Mar 1, 2011	27,969 shares, last reported balance as of Feb 28, 2011
Stanley Barshay	Mar 5, 2010	72,765 shares, last reported balance as of Mar 5, 2010
Samuel Thier	Nov 5, 2009	20 shares, last reported balance as of Nov 3, 2009
Eugene McGrath	Nov 4, 2009	No balance on record
Robert Van Oordt	Nov 4, 2009	No balance on record
Arthur Weinbach	Nov 4, 2009	No balance on record
Ron Cheeley	Nov 4, 2009	No balance on record
Brent Saunders	Nov 4, 2009	No balance on record
Robert Bertolini	Nov 4, 2009	No balance on record
Fred Hassan	Nov 4, 2009	No balance on record
Kathryn Turner	Nov 4, 2009	No balance on record
Carrie Cox	Nov 4, 2009	No balance on record
Thomas Sabatino Jr.	Nov 4, 2009	No balance on record
Thomas Colligan	Nov 4, 2009	No balance on record
Steven Koehler	Nov 4, 2009	No balance on record
Thomas Koestler	Nov 4, 2009	No balance on record
Lori Queisser	Nov 4, 2009	No balance on record
Antonio Perez	Nov 4, 2009	No balance on record
Jack Stahl	Nov 4, 2009	No balance on record
Hans Becherer	Jun 2, 2009	48,483 shares, last reported balance as of Nov 13, 2006
Carl Mundy Jr.	Jun 2, 2009	21,910 shares, last reported balance as of Jun 1, 2009
Philip Leder	Dec 1, 2008	24,003 shares, last reported balance as of Dec 1, 2008
Cecil Pickett	Aug 29, 2006	68,541 shares, last reported balance as of Aug 25, 2006
Richard Osborne	May 23, 2006	93,832 shares, last reported balance as of May 20, 2006
Douglas Gingerella	Dec 2, 2005	20,913 shares, last reported balance as of Dec 1, 2005
Thomas Kelly	Jun 9, 2004	34,786 shares, last reported balance as of Jun 9, 2004
David Komansky	Apr 29, 2004	20,999 shares, last reported balance as of Apr 27, 2004
Donald Miller	Apr 29, 2004	21,239 shares, last reported balance as of Apr 27, 2004
Joseph Connors	Apr 16, 2004	194,597 shares, last reported balance as of Mar 8, 2004
John Ryan	Dec 23, 2003	57,463 shares, last reported balance as of Dec 22, 2003
Geraldine Foster	Dec 23, 2003	40,279 shares, last reported balance as of Dec 1, 2003
Richard Zahn	Dec 4, 2003	37,563 shares, last reported balance as of Dec 1, 2003
Jack Wyszomierski	Dec 3, 2003	120,081 shares, last reported balance as of Dec 1, 2003
Daniel Nichols	Oct 29, 2003	No balance on record
Joseph Larosa		No balance on record
Donald Lemma		No balance on record
Kevin Moore		No balance on record

Spotted something wrong on this page? Report an error. We check every report against the SEC filing and list what we fix in the corrections log.

Merck & Co. insiders sold $72.0M in the past 12 months. How much of their stake is that?

What stands out

Who sold, and how much of their stake

Selling by month

Common questions

Is the Merck & Co. CEO selling stock?

Why are Merck & Co. insiders selling?

Are any Merck & Co. insiders buying?

How much of their stake did Merck & Co. insiders sell?

The evidence

No plan disclosed · $72.0M

Taxes

Sales by month