Johannes Jacobus Oosthuizen serves as Executive at Merck & Co., Inc., where they oversee executive responsibilities. Since joining the company, Johannes Jacobus Oosthuizen has executed 32 insider transactions totaling $9.5M, demonstrating a bearish approach to their equity position. Their most recent transaction on Feb 6, 2026 involved selling 15,000 shares valued at $1.8M.
Johannes Jacobus Oosthuizen currently holds 21,197.39 shares of Merck & Co., Inc. (MRK), valued at approximately $0. This represents their equity stake as Executive.
Based on SEC Form 4 filings, Johannes Jacobus Oosthuizen has been a net seller of MRK stock. They have purchased $0 and sold $9.5M worth of shares.
Johannes Jacobus Oosthuizen's most recent insider trade was on Feb 6, 2026, when they sold 15,000 shares at $121.87 per share.
Get notified when new Form 4 filings are submitted
| $107.40 |
| Discretionary |
| May 4, 2024 | MRK | $116.3K | Option Exercise | 912 | $127.51 | Discretionary |
| May 4, 2024 | MRK | $57.4K | Payment | 450 | $127.51 | Discretionary |
| Feb 2, 2024 | MRK | $620.1K | Option Exercise | 7,119 | $87.10 | Discretionary |
| Feb 2, 2024 | MRK | $519.4K | Option Exercise | 7,045 | $73.73 | Discretionary |
| Feb 2, 2024 | MRK | $2.4M | Sale | 18,959 | $127.18 | Discretionary |
| Feb 2, 2024 | MRK | $510.4K | Option Exercise | 6,773 | $75.36 | Discretionary |
| Jan 22, 2024 | MRK | $374.2K | Award | 3,133 | $119.43 | Discretionary |
| Nov 9, 2023 | MRK | $213.1K | Sale | 2,081 | $102.38 | Discretionary |
| Oct 30, 2023 | MRK | $94.1K | Option Exercise | 915 | $102.82 | Discretionary |
| Oct 30, 2023 | MRK | $46.4K | Payment | 451 | $102.82 | Discretionary |
| May 4, 2023 | MRK | $52.8K | Payment | 447 | $118.22 | Discretionary |
| May 4, 2023 | MRK | $107.2K | Option Exercise | 907 | $118.22 | Discretionary |
| May 1, 2023 | MRK | $49.3K | Payment | 427 | $115.47 | Discretionary |
| May 1, 2023 | MRK | $100.0K | Option Exercise | 866 | $115.47 | Discretionary |
| Jan 23, 2023 | MRK | $229.8K | Award | 2,091 | $109.88 | Discretionary |
| Nov 9, 2022 | MRK | $185.3K | Sale | 1,795 | $103.21 | Discretionary |
| Nov 7, 2022 | MRK | $0 | Option Exercise | 17,455 | $N/A | Discretionary |
| Nov 7, 2022 | MRK | $0 | Option Exercise | 13,540 | $N/A | Discretionary |
| Nov 7, 2022 | MRK | $0 | Option Exercise | 7,045 | $N/A | Discretionary |
| Nov 7, 2022 | MRK | $4.5M | Sale | 45,561 | $99.47 | Discretionary |
| Nov 7, 2022 | MRK | $0 | Option Exercise | 14,703 | $N/A | Discretionary |
| Oct 30, 2022 | MRK | $92.0K | Option Exercise | 913 | $100.77 | Discretionary |
| Oct 30, 2022 | MRK | $45.3K | Payment | 450 | $100.77 | Discretionary |
| Oct 28, 2022 | MRK | $364.1K | Sale | 3,633 | $100.21 | Discretionary |
| May 4, 2022 | MRK | $38.9K | Payment | 447 | $87.10 | Discretionary |
| May 4, 2022 | MRK | $79.0K | Option Exercise | 907 | $87.10 | Discretionary |
| May 3, 2022 | MRK | $67.8K | Option Exercise | 773 | $87.65 | Discretionary |
| May 3, 2022 | MRK | $33.4K | Payment | 381 | $87.65 | Discretionary |