Home

Johannes Jacobus Oosthuizen

CIK 1916310 · EVP, Oncology & Int?l · last filed 2026-05-07

Johannes Jacobus Oosthuizen is an EVP, Oncology & Int?l who has filed 28 SEC Form 4 insider transactions across 1 company since 2022. The most recent filing, for MRK, was dated May 7, 2026. Across all open-market trades the lifetime net is −$10.2M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $3.3M across reported positions. 29 SEC filings were submitted jointly with Merck & Co., Inc.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

Loading insider history…
Disclosed Exposure

$3.29M

Companies

1

Total Filings

28

Lifetime Open-Market Net

-$10.25M

Filer Profile

Reported Address
126 EAST LINCOLN AVENUE
P.O. BOX 2000
RAHWAY, NJ 07065
Related Filers
Merck & Co., Inc. — 29 joint filings, latest 2026-05-07
Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
MRK EVP, Oncology & Int?l 21,895 $150.33 $3.29M -$10.25M 24 2026-05-07

Recent Filings

28 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2026-05-07 MRK Grant (A) — $0 EDGAR
2026-05-01 MRK Mixed +698 $76.8K EDGAR
2026-02-06 MRK Notice (144) −15,000 -$1.83M EDGAR
2026-02-06 MRK Sell (S) −15,000 -$1.83M EDGAR
2026-01-28 MRK Grant (A) +5,026 $539.8K EDGAR
2025-05-01 MRK Grant (A) — $0 EDGAR
2025-02-20 MRK Sell (S) −8,500 -$714.7K EDGAR
2025-02-19 MRK Notice (144) −8,500 -$714.7K EDGAR
2025-02-11 MRK Mixed +6,598 $575.9K EDGAR
2025-01-29 MRK Grant (A) +8,664 $848.6K EDGAR
Showing 1–10 of 28
Page 1 of 3
Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.