← Unusual insider activity · Company hub
MRK Merck & Co., Inc.
Insider figures are trailing 90 days, open-market Form 4 only. Institutional figures are the latest reported quarter. These windows are not simultaneous.
-$30.0M net selling - trailing 90 days
0 buyers - 5 unique sellers
Historical context: most recent complete month (2026-08) is the 7th percentile of this ticker's monthly net P/S flow over 23 complete months (limited history). Lower percentiles are more selling; higher are more buying.
Institutional activity: not available - insufficient comparable institutions for the latest complete quarter.
open-market Form 4 only - grants, exercises, tax withholding excluded. ~ derived from SEC-reported shares x price.
Institutional activity: not available - insufficient comparable institutions for the latest complete quarter.
Who is responsible
| Insider | Role | Net activity | Rows |
|---|---|---|---|
| Zachary Jennifer | EVP, General Counsel | -~$10.7M | 1 |
| Williams David Michael | EVP,Chief Info&Digital Officer | -~$6.8M | 3 |
| DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | -~$6.7M | 8 |
| Guindo Chirfi | EVP, Access, Policy & Comms | -~$3.3M | 2 |
| Maraldo David R. | EVP & Pres. MMD | -~$2.4M | 3 |
Transactions
| Date | Insider | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 8/13/2026 | Guindo Chirfi | EVP, Access, Policy & Comms | S | -10000 | 135 | ~$1.4M |
| 8/12/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | 2 reported sale rows | 11699 | — | ~$1.5M |
| 8/12/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | S | -11099 | 131.6128 | ~$1.5M |
| 8/12/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | S | -600 | 132.0367 | ~$79K |
| 8/12/2026 | Zachary Jennifer | EVP, General Counsel | S | -80315 | 133.4557 | ~$10.7M |
| 8/11/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | 2 reported sale rows | 12837 | — | ~$1.7M |
| 8/11/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | S | -7410 | 131.3313 | ~$1.0M |
| 8/11/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | S | -5427 | 132.3496 | ~$0.7M |
| 8/10/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | S | -20784 | 130.4345 | ~$2.7M |
| 8/6/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | 3 reported sale rows | 6050 | — | ~$0.8M |
| 8/6/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | S | -805 | 131.0216 | ~$0.1M |
| 8/6/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | S | -300 | 131.0233 | ~$39K |
| 8/6/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | S | -4945 | 130.2312 | ~$0.6M |
| 8/6/2026 | Guindo Chirfi | EVP, Access, Policy & Comms | S | -15000 | 131 | ~$2.0M |
| 8/5/2026 | Maraldo David R. | EVP & Pres. MMD | 3 reported sale rows | 18706 | — | ~$2.4M |
| 8/5/2026 | Maraldo David R. | EVP & Pres. MMD | S | -2686 | 128.7179 | ~$0.3M |
| 8/5/2026 | Maraldo David R. | EVP & Pres. MMD | S | -9709 | 128.7179 | ~$1.2M |
| 8/5/2026 | Maraldo David R. | EVP & Pres. MMD | S | -6311 | 128.7179 | ~$0.8M |
| 8/5/2026 | Williams David Michael | EVP,Chief Info&Digital Officer | 3 reported sale rows | 52847 | — | ~$6.8M |
| 8/5/2026 | Williams David Michael | EVP,Chief Info&Digital Officer | S | -13542 | 128.7707 | ~$1.7M |
| 8/5/2026 | Williams David Michael | EVP,Chief Info&Digital Officer | S | -34705 | 128.7707 | ~$4.5M |
| 8/5/2026 | Williams David Michael | EVP,Chief Info&Digital Officer | S | -4600 | 128.7707 | ~$0.6M |
| 2/12/2026 | Guindo Chirfi | Chief Marketing Officer | S | -10000 | 121.4562 | ~$1.2M |
| 2/10/2026 | Li Dean Y | Executive VP & President, MRL | S | -10235 | 117.5226 | ~$1.2M |
| 2/9/2026 | Zachary Jennifer | EVP, General Counsel | 3 reported sale rows | 121573 | — | ~$14.5M |
| 2/9/2026 | Zachary Jennifer | EVP, General Counsel | S | -38835 | 119.1522 | ~$4.6M |
| 2/9/2026 | Zachary Jennifer | EVP, General Counsel | S | -25946 | 119.1522 | ~$3.1M |
| 2/9/2026 | Zachary Jennifer | EVP, General Counsel | S | -56792 | 119.1522 | ~$6.8M |
| 2/9/2026 | Guindo Chirfi | Chief Marketing Officer | S | -10000 | 118.4101 | ~$1.2M |
| 2/6/2026 | Oosthuizen Johannes Jacobus | President, U.S. Market | S | -15000 | 121.8661 | ~$1.8M |
| 2/6/2026 | DeLuca Richard R. | EVP&Pres, Merck Animal Heallth | S | -37685 | 120.9241 | ~$4.6M |
| 2/6/2026 | Williams David Michael | EVP,Chief Info&Digital Officer | S | -5000 | 121.905 | ~$0.6M |
| 2/5/2026 | Guindo Chirfi | Chief Marketing Officer | S | -20000 | 121.8838 | ~$2.4M |
| 2/4/2026 | Smart Dalton E. III | SVP Fin. - Global Controller | 2 reported sale rows | 6400 | — | ~$0.8M |
| 2/4/2026 | Smart Dalton E. III | SVP Fin. - Global Controller | S | -2400 | 119.675 | ~$0.3M |
| 2/4/2026 | Smart Dalton E. III | SVP Fin. - Global Controller | S | -4000 | 119.675 | ~$0.5M |
| 2/4/2026 | Davis Robert M | Chairman, CEO & President | 2 reported sale rows | 47434 | — | ~$5.6M |
| 2/4/2026 | Davis Robert M | Chairman, CEO & President | S | -32462 | 118.3513 | ~$3.8M |
| 2/4/2026 | Davis Robert M | Chairman, CEO & President | S | -14972 | 117.3796 | ~$1.8M |
| 2/4/2026 | Li Dean Y | Executive VP & President, MRL | S | -15087 | 118.7661 | ~$1.8M |
| 2/4/2026 | Litchfield Caroline | EVP & CFO | S | -41997 | 119.6112 | ~$5.0M |
| 11/10/2025 | Downing Cristal N | Chief Comm. & Public Afrs Ofcr | S | -7085 | 87 | ~$0.6M |
| 11/3/2025 | Williams David Michael | EVP,Chief Info&Digital Officer | S | -8614 | 83.5895 | ~$0.7M |
| 4/25/2025 | Smart Dalton E. III | SVP Fin. - Global Controller | S | -4262 | 82.76 | ~$0.4M |
| 2/19/2025 | Oosthuizen Johannes Jacobus | President, U.S. Market | S | -8500 | 84.0876 | ~$0.7M |
| 2/13/2025 | Williams David Michael | EVP,Chief Info&Digital Officer | S | -6000 | 85.3428 | ~$0.5M |
| 2/6/2025 | THULIN INGE G | — | P | 2832.861 | 88.25 | ~$0.2M |
| 2/6/2025 | Downing Cristal N | Chief Comm. & Public Afrs Ofcr | S | -2361 | 88.7551 | ~$0.2M |
| 2/5/2025 | BAKER DOUGLAS M JR | — | P | 15000 | 88.5 | ~$1.3M |