Merck & Co. Inc. (MRK) insider trading
Recent insider transactions reported to the SEC on Form 4 — directors and officers buying or selling their own company’s stock. Sourced directly from public SEC filings, latest filed Oct 1, 2026.
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- Filings shown
- 10
- Open-market buys
- 0
- Open-market sells
- 17
Counts cover the 10 most recent Form 4 filings Tradune holds for MRK (filed Aug 7 – Oct 1, 2026). No completed check of MRK's Form 4 list on SEC EDGAR is on record yet; the latest MRK filing Tradune holds was filed Oct 1, 2026. This is not guaranteed to be the complete record — see MRK's full Form 4 filing history on SEC EDGAR.
Open-market activity, last 90 days
Purchases (Form 4 code P) and sales (code S) on the 10 filings Tradune holds for MRK filed Aug 7 – Oct 1, 2026. Grants, exercises, tax withholding and the other Form 4 transaction codes are left out.
17 open-market sales by Rule 10b5-1 checkbox
- On filings with the 10b5-1 box checked
- 0 sales· 0 sh
- checkbox disclosed
- On filings with the box not checked
- 0 sales· 0 sh
- not proof that no plan exists
- Not comparable
- 17 sales· 228,238 sh
- filed before Apr 1, 2023, or no checkbox value in the filing data
Counts are Form 4 lines as filed. The checkbox is one per filing, so every sale on a filing with the box checked is counted there even if only some of its transactions were under a plan; it records what the filer disclosed, and the three categories are not a judgement about why a sale was made.
| Insider | Buys | Sells | Shares bought | Shares sold | Value |
|---|---|---|---|---|---|
| Richard R. DeLucaEVP&Pres, Merck Animal Heallth | 0 | 8 | — | 51,370 | −$6,731,142 |
| David Michael WilliamsEVP,Chief Info&Digital Officer | 0 | 3 | — | 52,847 | −$6,805,145 |
| David R. MaraldoEVP & Pres. MMD | 0 | 3 | — | 18,706 | −$2,407,797 |
| Chirfi GuindoEVP, Access, Policy & Comms | 0 | 2 | — | 25,000 | −$3,315,000 |
| Jennifer ZacharyEVP, General Counsel | 0 | 1 | — | 80,315 | −$10,718,495 |
Value = shares × the price reported on each Form 4 (+ purchases, − sales); every open-market line in this window disclosed a price.
Summarises ~90 days of public SEC Form 4 activity — more distinct buyers, officer involvement and net buying score higher. A description of filing activity, not a rating or buy signal. How this score is computed →
How to read this: an open-market purchase (Form 4 code P) is a buy at the market price with the insider’s own money, as opposed to a grant, award or option exercise; an open-market sale is code S. When two or more distinct insiders report open-market purchases in the same 90-day window, this site labels that a cluster — a definition, not a forecast; see insider cluster buying. “Held after” is Form 4 Table I column 5; “Change” = shares ÷ holdings before the trade (held after − shares for an acquisition, held after + shares for a disposition).
Insider Buying at MRK
No open-market insider purchases (Form 4 code P) were reported for MRK in the trailing 90 days. The filings below may include other transaction types — sales, grants, option exercises, and tax withholding — shown for completeness; they are not open-market purchases.
Recent Form 4 filings
Source: SEC EDGAR Form 4 · transaction codes explained
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award Phantom Stock | 56 | $145.31 | — | — | Sep 30, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award Phantom Stock | 112 | $145.31 | — | — | Sep 30, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award Phantom Stock | 206 | $145.31 | — | — | Sep 30, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 10,000 | $135.00 | — | — | Aug 13, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Option exercise | 41,494 | $117.89 | — | — | Aug 12, 2026 |
| Option exercise Stock Option (Right to Buy) | 13,433 | — | — | — | Aug 12, 2026 |
| Option exercise Stock Option (Right to Buy) | 41,494 | — | — | — | Aug 12, 2026 |
| Open-market sale | 80,315 | $133.46 | — | — | Aug 12, 2026 |
| Option exercise | 13,433 | $84.71 | — | — | Aug 12, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 600 | $132.04 | — | — | Aug 12, 2026 |
| Open-market sale | 11,099 | $131.61 | — | — | Aug 12, 2026 |
| Open-market sale | 5,427 | $132.35 | — | — | Aug 11, 2026 |
| Open-market sale | 7,410 | $131.33 | — | — | Aug 11, 2026 |
| Open-market sale | 20,784 | $130.43 | — | — | Aug 10, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 300 | $131.02 | — | — | Aug 6, 2026 |
| Open-market sale | 805 | $131.02 | — | — | Aug 6, 2026 |
| Open-market sale | 4,945 | $130.23 | — | — | Aug 6, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 15,000 | $131.00 | — | — | Aug 6, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 2,686 | $128.72 | — | — | Aug 5, 2026 |
| Option exercise | 2,686 | $84.71 | — | — | Aug 5, 2026 |
| Open-market sale | 9,709 | $128.72 | — | — | Aug 5, 2026 |
| Option exercise | 9,709 | $87.10 | — | — | Aug 5, 2026 |
| Open-market sale | 6,311 | $128.72 | — | — | Aug 5, 2026 |
| Option exercise | 6,311 | $73.73 | — | — | Aug 5, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 34,705 | $128.77 | — | — | Aug 5, 2026 |
| Option exercise | 34,705 | $73.73 | — | — | Aug 5, 2026 |
| Open-market sale | 13,542 | $128.77 | — | — | Aug 5, 2026 |
| Option exercise | 13,542 | $75.36 | — | — | Aug 5, 2026 |
| Open-market sale | 4,600 | $128.77 | — | — | Aug 5, 2026 |
| Option exercise | 4,600 | $77.62 | — | — | Aug 5, 2026 |
Insider filings reported around the same time
Other companies whose most recent Form 4 was filed closest to MRK's (Oct 1, 2026).
Frequently asked about MRK insider activity
How many insiders bought MRK stock in the last 90 days?
No open-market purchases (Form 4 code P) of MRK shares were reported by Merck & Co. Inc. insiders in the trailing 90 days. The 10 filings shown on this page cover other transaction types — sales, grants, option exercises, and tax withholding.
Who filed the most recent Form 4 for MRK?
The most recent Form 4 on this page was filed by Mary Ellen Coe (Director) on Oct 1, 2026, reporting 1 transaction. The original document is linked from the filing list above on SEC EDGAR. Amended filings (Form 4/A) may later revise reported figures.
What was the largest open-market MRK insider sale shown?
The largest open-market sale among the filings shown was 80,315 MRK shares at $133.46 (about $10,718,495) by Jennifer Zachary (EVP, General Counsel) on Aug 12, 2026. Value is shares × the price reported on the Form 4; trades may be made under a prearranged Rule 10b5-1 plan.
New to Form 4s? The transaction codes, the 90-day window and the 0–100 score are defined on the insider-activity score methodology page.
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Track MRK insider filings free →This score summarizes SEC Form 4 filing activity over the trailing 90 days. It is descriptive, not predictive — not a rating, recommendation, or investment advice. Data: SEC EDGAR (public domain), as filed; amendments may revise figures. Tradune is not a registered investment adviser.
Data as filed; amended filings (Form 4/A) may revise figures. Sales may occur under prearranged Rule 10b5-1 trading plans.