Merck (MRK) insider buying and selling
Every Table I transaction reported by directors and officers of S&P 500 companies on SEC Form 4 filings (2 business days to file): each row labeled with its official transaction code, nothing filtered out beforehand.
Open-market purchases (code P) are the rare signal, in green; sales (code S) are common and often pre-scheduled (10b5-1). Table II (derivatives) is not included: its prices are exercise prices, not market values. Guide: insider buying.
| Date | Ticker | Insider | Role | Shares | Price | Amount | % of stake | Type / filing |
|---|
Download these transactions as CSV No account, no sign-up. The data is public: it comes from SEC Form 4 filings.
Merck & Co., Inc. (MRK) insider buying and selling: no purchases, 23 sales
72 Form 4 Table I transactions filed with the SEC by Merck & Co., Inc. insiders between 2025-11-04 and 2026-08-13 (15-month history): 0 open-market purchases and 23 sales, plus 49 transactions under other Form 4 codes, broken down one by one below. The largest open-market trade is a sale of $14.5M by Zachary Jennifer on 2026-02-09.
Merck insider buying and selling over the last 12 months
Between Oct 21, 2025 and Oct 20, 2026, Merck insiders filed 23 sales worth $72.0M on the open market, and no purchases.
The biggest seller was Zachary Jennifer (EVP, General Counsel): $25.2M in 2 sales, out of 11 different sellers.
The largest trade of the period was a sale of $14.5M on Feb 9, 2026, by Zachary Jennifer (EVP, General Counsel). Form 4 on sec.gov (0000310158-26-000046).
None of the 23 sales carries the 10b5-1 plan flag on the Form 4 (sales scheduled months ahead).
The last three months show 9 sales, against 0 in the three before. The latest sale from Aug 13, 2026.
Against its sector (Healthcare, 59 companies with an insider page on this site), over the same dates the median is 9 sales and 0 purchases on the open market. Merck has more sales than 49 of the other 58, ranks 12 of 59 by net dollars sold, and 19 of the 59 have at least one purchase.
The 20 most important trades
With no open-market purchases, the table starts with MRK's sales, largest first. The full history is in the tool above, already searched.
See all 72 MRK trades in the full history →
| Trade date | Filed | Insider | Role | Amount | Code | Filing |
|---|---|---|---|---|---|---|
| 2026-02-09 | 2026-02-09 | Zachary Jennifer | EVP, General Counsel | $14.5M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.9600 to $119.5100, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-08-12 | 2026-08-13 | Zachary Jennifer | EVP, General Counsel | $10.7M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $133.0300 to $133.5000, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-08-05 | 2026-08-07 | Williams David Michael | EVP, Chief Info&Digital Officer | $6.8M | S — Open-market saleForm 4 footnoteF1 The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $128.7050 to $128.9700, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-02-04 | 2026-02-06 | Davis Robert M | Chairman, CEO & President | $5.6M | S — Open-market sale2 Form 4 footnotesF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $116.9600 to $117.9500, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. F2 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.0000 to $118.7100, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-02-04 | 2026-02-06 | Litchfield Caroline | EVP & CFO | $5.0M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.5400 to $119.7800, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-02-06 | 2026-02-06 | Deluca Richard R. | EVP&Pres, Merck Animal Heallth | $4.6M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $120.7350 to $121.3054, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-08-10 | 2026-08-12 | Deluca Richard R. | EVP&Pres, Merck Animal Heallth | $2.7M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $130.0000 to $130.9500, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-02-05 | 2026-02-06 | Guindo Chirfi | Chief Marketing Officer | $2.4M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.8400 to $121.9700, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-08-05 | 2026-08-07 | Maraldo David R. | EVP & Pres. MMD | $2.4M | S — Open-market saleForm 4 footnoteF1 The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $128.6400 to $128.8500, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in the footnote. | SEC |
| 2026-08-06 | 2026-08-07 | Guindo Chirfi | EVP, Access, Policy & Comms | $2.0M | S — Open-market sale | SEC |
| 2026-02-06 | 2026-02-06 | Oosthuizen Johannes Jacobus | President, U.S. Market | $1.8M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.8200 to $121.9500, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-02-04 | 2026-02-06 | Li Dean Y | Executive VP & President, MRL | $1.8M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.7200 to $118.8300, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. | SEC |
| 2026-08-11 | 2026-08-12 | Deluca Richard R. | EVP&Pres, Merck Animal Heallth | $1.7M | S — Open-market sale2 Form 4 footnotesF2 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $131.0000 to $131.9800, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. F3 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $132.0000 to $132.6514, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-08-12 | 2026-08-12 | Deluca Richard R. | EVP&Pres, Merck Animal Heallth | $1.5M | S — Open-market sale2 Form 4 footnotesF4 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $131.0000 to $131.9950, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. F5 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $132.0000 to $132.0700, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-08-13 | 2026-08-13 | Guindo Chirfi | EVP, Access, Policy & Comms | $1.4M | S — Open-market sale | SEC |
| 2026-02-12 | 2026-02-12 | Guindo Chirfi | Chief Marketing Officer | $1.2M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.4400 to $121.5150, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-02-10 | 2026-02-10 | Li Dean Y | Executive VP & President, MRL | $1.2M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $117.5200 to $117.5550, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-02-09 | 2026-02-09 | Guindo Chirfi | Chief Marketing Officer | $1.2M | S — Open-market saleForm 4 footnoteF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.4000 to $118.4502, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-08-06 | 2026-08-10 | Deluca Richard R. | EVP&Pres, Merck Animal Heallth | $789k | S — Open-market sale3 Form 4 footnotesF1 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $131.0000 to $131.0700, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. F2 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $130.0000 to $130.9200, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. F3 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $131.0000 to $131.0300, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote. | SEC |
| 2026-02-04 | 2026-02-06 | Smart Dalton E. Iii | SVP Fin. - Global Controller | $766k | S — Open-market sale | SEC |
The period balance: money in, money out
In the Form 4 filings submitted between Nov 4, 2025 and Aug 13, 2026 there is not one open-market purchase of Merck & Co., Inc.: 23 sales worth $72.0M and zero dollars bought.
Only codes P and S count, where an insider puts in or takes out their own money. A selling balance like Merck & Co., Inc.'s is the norm in the S&P 500, where much of the pay comes as stock. It is not a recommendation to buy or sell: it is what was filed.
Every transaction, code by code
| Code | What it means | Trades | Reported amount |
|---|---|---|---|
| M | Option exercise | 23 | $35.3M |
| S | Open-market sale | 23 | $72.0M |
| F | Tax withholding (shares surrendered for taxes) | 15 | $2.6M |
| A | Grant or award | 11 | $16.0M |
| Total | Everything filed in the period | 72 | $125.9M |
All 72 rows carry an amount: the column adds up what was filed, no estimates. The code labels come from the SEC index.
Who has traded
Over the 15 months of history, 14 distinct people or entities have filed Merck & Co., Inc. transactions: none bought on the open market and 11 sold. Counted by CIK, the fixed number the SEC gives each filer, and not by name, which each filer types their own way.
Of the 11 who sold on the open market (23 sales in all), the three biggest sellers account for $44.6M of the $72.0M: 62% of the money in three people.
| Filer | Role | Transactions | Bought (count) | Sold (count) | Last filed |
|---|---|---|---|---|---|
| Zachary Jennifer | EVP, General Counsel | 7 | — | $25.2M (2) | 2026-08-13 |
| Deluca Richard R. | EVP&Pres, Merck Animal Heallth | 8 | — | $11.3M (5) | 2026-08-12 |
| Guindo Chirfi | EVP, Access, Policy & Comms | 8 | — | $8.2M (5) | 2026-08-13 |
| Williams David Michael | EVP, Chief Info&Digital Officer | 8 | — | $8.1M (3) | 2026-08-07 |
| Davis Robert M | Chairman, CEO & President | 4 | — | $5.6M (1) | 2026-05-01 |
| Litchfield Caroline | EVP & CFO | 5 | — | $5.0M (1) | 2026-05-01 |
| Li Dean Y | Executive VP & President, MRL | 6 | — | $3.0M (2) | 2026-05-01 |
| Maraldo David R. | EVP & Pres. MMD | 4 | — | $2.4M (1) | 2026-08-07 |
Shown here are the 8 who moved the most money, out of 14. The rest are in the full history, one link above. The name links to all their trades, in any company. "Transactions" counts any code; the money, open market only. Role: from their latest filing.
Month by month
By the month the trade was executed, not the month it was filed; months with no trades show zero. The busiest month was Feb 2026: 0 purchases and 12 sales, worth $40.7M. 12 of the 15 months have none.
| Month | Purchases | Amount | Sales | Amount |
|---|---|---|---|---|
| Aug 2025 | 0 | $0 | 0 | $0 |
| Sep 2025 | 0 | $0 | 0 | $0 |
| Oct 2025 | 0 | $0 | 0 | $0 |
| Nov 2025 | 0 | $0 | 2 | $1.3M |
| Dec 2025 | 0 | $0 | 0 | $0 |
| Jan 2026 | 0 | $0 | 0 | $0 |
| Feb 2026 | 0 | $0 | 12 | $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 | 0 | $0 | 9 | $30.0M |
| Sep 2026 | 0 | $0 | 0 | $0 |
| Oct 2026 | 0 | $0 | 0 | $0 |
The last month may be partial: a Form 4 is filed up to two business days later. The table does not say whether the pattern is good or bad; it says when it happened.
Merck & Co., Inc. (MRK) analysis page →
Other Healthcare companies with insider trades
All 500 are listed in the section index →
Which insiders are buying their own company stock →
How to read this data
None of the 20 sales in the table is flagged as scheduled (10b5-1 plan), the kind signed months ahead and executed automatically. Merck has no open-market purchase (code P) in the history, the most common case in the S&P 500: insiders are already paid in stock. The latest filing is from Aug 13, 2026, and a Form 4 arrives up to two business days after the trade.
17 of the 20 rows in the table carry footnotes from the Form 4 itself, folded into the code column and copied verbatim; a row with no footnote means the filing has none.
Guide: Insider buying · all guides
What is behind these trades
The concepts on this page, explained from scratch in the Academy. Free, no account.
- What the efficiency hypothesis says and what it does NOT sayIf an insider's purchase is public and anyone can read it, is there any information left in it? That is the exact question that brings people here.
- Who really moves the market: the types of investorWho sits on the other side of each order, and where a company's own insiders fit among them.
- Supply, demand and price: why it rises and falls constantlyHow a piece of news ends up inside the price, and why the reaction to a filed sale is rarely the one you would expect.
Source: SEC EDGAR Form 4. This is a list of public facts, not financial advice or a recommendation to buy or sell.