Johannes Jacobus Oosthuizen, President of U.S. Market, sold Merck & Co. ($MRK) shares once on the open market in the last year for a total of $1.8 million. His most recent sale occurred on February 6, 2026. These sales rank 3,671st among 11,700 insiders by value, well below the average of $8.6 million across 6.4 transactions. He made no open market purchases.
| Transaction Date | Company | Ticker | Insider Name | Title | Transaction Type | Security | Shares | Price | Shares Owned Following | Total Shares Outstanding | % of Owned | % of Outstanding |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feb. 6, 2026 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | S | Common Stock | 15000 | $121.87 | 21,197.3890 | 2,514,000,000 | 41.44% | 0.00% |
| Jan. 26, 2026 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | A | Common Stock | 5026 | $107.40 | 36,197.3890 | 2,514,000,000 | 16.12% | 0.00% |
| April 29, 2025 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | A | Restricted Stock Unit | 4132 | $0.00 | 4,132.0000 | 2,541,000,000 | 9999.99% | 0.00% |
| April 29, 2025 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | A | Stock Option (Right to Buy) | 18807 | $0.00 | 18,807.0000 | 2,541,000,000 | 9999.99% | 0.00% |
| Feb. 19, 2025 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | S | Common Stock | 8500 | $84.09 | 30,705.4740 | 2,541,000,000 | 21.68% | 0.00% |
| Feb. 8, 2025 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Restricted Stock Unit | 13002 | $0.00 | 0.0000 | 2,541,000,000 | 100.00% | 0.00% |
| Feb. 8, 2025 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | F | Common Stock | 6404 | $87.28 | 39,205.4740 | 2,541,000,000 | 14.04% | 0.00% |
| Feb. 8, 2025 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Common Stock | 13002 | $87.28 | 45,609.4740 | 2,541,000,000 | 39.87% | 0.00% |
| Jan. 27, 2025 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | A | Common Stock | 8664 | $97.94 | 32,607.4740 | 2,541,000,000 | 36.19% | 0.00% |
| May 4, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Restricted Stock Unit | 912 | $0.00 | 0.0000 | 2,547,000,000 | 100.00% | 0.00% |
| May 4, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | F | Common Stock | 450 | $127.51 | 23,820.9490 | 2,547,000,000 | 1.85% | 0.00% |
| May 4, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Common Stock | 912 | $127.51 | 24,270.9490 | 2,547,000,000 | 3.90% | 0.00% |
| April 30, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | A | Stock Option (Right to Buy) | 20508 | $0.00 | 20,508.0000 | 2,547,000,000 | 9999.99% | 0.00% |
| Feb. 2, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Common Stock | 7119 | $87.10 | 42,286.3450 | 2,547,000,000 | 20.24% | 0.00% |
| Feb. 2, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | S | Common Stock | 18959 | $127.18 | 23,327.3450 | 2,547,000,000 | 44.83% | 0.00% |
| Feb. 2, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Stock Option (Right to Buy) | 6773 | $0.00 | 0.0000 | 2,547,000,000 | 100.00% | 0.00% |
| Feb. 2, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Stock Option (Right to Buy) | 7045 | $0.00 | 7,049.0000 | 2,547,000,000 | 49.99% | 0.00% |
| Feb. 2, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Stock Option (Right to Buy) | 7119 | $0.00 | 14,240.0000 | 2,547,000,000 | 33.33% | 0.00% |
| Feb. 2, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Common Stock | 7045 | $73.73 | 35,167.3450 | 2,547,000,000 | 25.05% | 0.00% |
| Feb. 2, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Common Stock | 6773 | $75.36 | 28,122.3450 | 2,547,000,000 | 31.72% | 0.00% |
| Jan. 22, 2024 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | A | Common Stock | 3133 | $119.43 | 21,349.3450 | 2,547,000,000 | 17.20% | 0.00% |
| Nov. 9, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | S | Common Stock | 2081 | $102.38 | 18,190.6570 | 2,542,000,000 | 10.27% | 0.00% |
| Oct. 30, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Restricted Stock Unit | 915 | $0.00 | 0.0000 | 2,542,000,000 | 100.00% | 0.00% |
| Oct. 30, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Common Stock | 915 | $102.82 | 20,722.6570 | 2,542,000,000 | 4.62% | 0.00% |
| Oct. 30, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | F | Common Stock | 451 | $102.82 | 20,271.6570 | 2,542,000,000 | 2.18% | 0.00% |
| May 4, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Restricted Stock Unit | 907 | $0.00 | 912.0000 | 2,542,000,000 | 49.86% | 0.00% |
| May 4, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | F | Common Stock | 447 | $118.22 | 19,759.7480 | 2,542,000,000 | 2.21% | 0.00% |
| May 4, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Common Stock | 907 | $118.22 | 20,206.7480 | 2,542,000,000 | 4.70% | 0.00% |
| May 2, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | A | Stock Option (Right to Buy) | 20747 | $0.00 | 20,747.0000 | 2,542,000,000 | 9999.99% | 0.00% |
| May 1, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | F | Common Stock | 427 | $115.47 | 19,299.7480 | 2,542,000,000 | 2.16% | 0.00% |
| May 1, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Restricted Stock Unit | 866 | $0.00 | 0.0000 | 2,542,000,000 | 100.00% | 0.00% |
| May 1, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | M | Common Stock | 866 | $115.47 | 19,726.7480 | 2,542,000,000 | 4.59% | 0.00% |
| Jan. 23, 2023 | Merck & Co., Inc. | $MRK | Oosthuizen Johannes Jacobus | President, U.S. Market | A | Common Stock | 2091 | $109.88 | 18,821.8810 | 2,542,000,000 | 12.50% | 0.00% |