Summary
Updated Aug 31, 2026
Johannes Jacobus Oosthuizen is EVP, Oncology & Int?l of Merck & Co., Inc. (MRK). 4 SEC Form 4 filings on record, most recently on 7 May 2026. Most recent open-market trade: sold $1.83M of MRK on 6 February 2026. Lifetime open-market sales: $1.83M.
Recent Transactions
4Every recent SEC Form 4 transaction Johannes Jacobus Oosthuizen has reported, most recent first.
Trading Pattern
InsiderAlpha's records for Johannes Jacobus Oosthuizen go back to 2026: 4 primary Form 4 filings, an average of 4.0 per year. No transaction on record carries a Rule 10b5-1 flag - the filings look discretionary rather than pre-scheduled, which makes their timing more informative as a signal.
Other Insiders Active in the Same Stocks
Insiders who reported open-market trades in the last 12 months at the companies Johannes Jacobus Oosthuizen files at. Multiple unrelated insiders buying the same stock within a short window, cluster buying, has historically been one of the strongest Form 4 signals.
- Jennifer Zachary - $25.20M of MRK open-market activity in the last 12 months
- Richard R. Deluca - $11.29M of MRK open-market activity in the last 12 months
- Chirfi Guindo - $8.15M of MRK open-market activity in the last 12 months
- David Michael Williams - $8.13M of MRK open-market activity in the last 12 months
- Robert M. Davis - $5.60M of MRK open-market activity in the last 12 months
- Caroline Litchfield - $5.02M of MRK open-market activity in the last 12 months
More Notable Insiders
Other corporate insiders with significant SEC Form 4 track records on InsiderAlpha:
Frequently Asked Questions
Who is Johannes Jacobus Oosthuizen?
Johannes Jacobus Oosthuizen is a corporate insider, tracked as EVP, Oncology & Int?l of Merck & Co., Inc. (MRK). InsiderAlpha holds 4 primary Form 4 filings for them, the earliest from 2026, updated as new SEC EDGAR filings are processed.
When did Johannes Jacobus Oosthuizen last file a Form 4?
The most recent primary Form 4 on record is dated 7 May 2026, one of 4 filings going back to 2026.
Has Johannes Jacobus Oosthuizen been buying or selling stock?
Recorded transactions: 0 open-market purchases and 1 open-market sale ($1.83M) across all tracked filings.
Where can I see all of Johannes Jacobus Oosthuizen's SEC filings?
All Form 4 filings, transaction values, and 10b5-1 plan flags are listed on this page and updated in real time as new SEC EDGAR filings are processed.
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