Kastelein Johannes Jacob Pieter
Director · Officer · NAMS
As of 2026-09-16, Kastelein Johannes Jacob Pieter has 37 Form 4 transactions on record across 1 company — 22 in the trailing 12 months.
Everything this person has disclosed to the SEC on Form 4 — across every company they file for — reconstructed from the public record. A filing history, not a tip sheet.
Pattern in the record: open-market sales filed in August in multiple years since 2025 — a recurring calendar cadence, more consistent with scheduled activity than a one-off decision.
Reconstructed holdings
Reconstructed from this person's own Form 4 filings — the total each filing reported owning afterward, priced at the close on the as-of date shown. A filed position can lag the real one.
Direct and indirect holdings (e.g. through a trust or fund) are tagged separately, as filed.
Trades by company
Filing ledger
| Date | Company | Action | Shares @ price | Value | Ownership Δ | Owned after | Filing |
|---|---|---|---|---|---|---|---|
| 2026-08-24 | NAMS | Sale | 125,000 @ $26.91 | $3.4M | −64.3% of holding | 69,302 | Form 4 |
| 2026-03-09 | NAMS | Sale | 101,409 @ $30.29 | $3.1M | −59.4% of holding | 69,302 | Form 4 |
| 2026-03-06 | NAMS | Sale | 94,124 @ $30.32 | $2.9M | −57.6% of holding | 69,302 | Form 4 |
| 2026-03-05 | NAMS | Sale | 104,467 @ $30.30 | $3.2M | −60.1% of holding | 69,302 | Form 4 |
| 2026-02-20 | NAMS | Sale | 30,789 @ $35.46 | $1.1M | −36.5% of holding | 53,500 | Form 4 |
| 2026-02-20 | NAMS | Sale | 14,692 @ $35.00 | $514K | −14.8% of holding | 84,289 | Form 4 |
| 2026-01-05 | NAMS | Sale | 6,000 @ $33.25 | $200K | −7.5% of holding | 73,481 | Form 4 |
| 2025-08-22 | NAMS | Sale | 42,342 @ $25.08 | $1.1M | −35.5% of holding | 76,960 | Form 4 |
| 2025-08-22 | NAMS | Sale | 7,658 @ $25.49 | $195K | −10.0% of holding | 69,302 | Form 4 |
| 2025-08-21 | NAMS | Sale | 50,000 @ $24.29 | $1.2M | −29.5% of holding | 119,302 | Form 4 |
27 award / exercise / gift records — not counted as purchases
| Date | Company | Action | Shares | Owned after | Filing |
|---|---|---|---|---|---|
| 2026-08-24 | NAMS | Option exercise | 125,000 | 395,229 | Form 4 |
| 2026-08-24 | NAMS | Option exercise | 125,000 | 194,302 | Form 4 |
| 2026-08-24 | NAMS | Option exercise | 125,000 | 194,302 | Form 4 |
| 2026-03-09 | NAMS | Option exercise | 101,409 | 520,229 | Form 4 |
| 2026-03-09 | NAMS | Option exercise | 101,409 | 170,711 | Form 4 |
| 2026-03-09 | NAMS | Option exercise | 101,409 | 170,711 | Form 4 |
| 2026-03-06 | NAMS | Option exercise | 94,124 | 621,638 | Form 4 |
| 2026-03-06 | NAMS | Option exercise | 94,124 | 163,426 | Form 4 |
| 2026-03-06 | NAMS | Option exercise | 94,124 | 163,426 | Form 4 |
| 2026-03-05 | NAMS | Option exercise | 104,467 | 715,762 | Form 4 |
| 2026-03-05 | NAMS | Option exercise | 104,467 | 173,769 | Form 4 |
| 2026-03-05 | NAMS | Option exercise | 104,467 | 173,769 | Form 4 |
| 2026-01-07 | NAMS | Award / grant | 115,000 | 115,000 | Form 4 |
| 2026-01-07 | NAMS | Award / grant | 25,500 | 98,981 | Form 4 |
| 2026-01-07 | NAMS | Award / grant | 25,500 | 98,981 | Form 4 |
| 2025-03-26 | NAMS | Award / grant | 19,302 | 169,302 | Form 4 |
| 2025-03-26 | NAMS | Option exercise | 45,481 | 79,481 | Form 4 |
| 2025-03-26 | NAMS | Award / grant | 45,481 | 45,481 | Form 4 |
| 2025-03-26 | NAMS | Option exercise | 45,481 | 0 | Form 4 |
| 2025-03-26 | NAMS | Award / grant | 45,481 | 45,481 | Form 4 |
| 2025-03-26 | NAMS | Option exercise | 45,481 | 0 | Form 4 |
| 2025-03-24 | NAMS | Option exercise | 150,000 | 820,229 | Form 4 |
| 2025-03-24 | NAMS | Option exercise | 150,000 | 150,000 | Form 4 |
| 2025-03-24 | NAMS | Option exercise | 150,000 | 150,000 | Form 4 |
| 2025-01-07 | NAMS | Award / grant | 34,000 | 34,000 | Form 4 |
| 2025-01-07 | NAMS | Award / grant | 34,000 | 34,000 | Form 4 |
| 2025-01-02 | NAMS | Award / grant | 200,000 | 200,000 | Form 4 |
Source: SEC Form 4 filings. Each row links to its original filing.
Research tool, not investment advice — historical frequencies, not recommendations. A product of Marovel Technologies LLC. Full terms.