Sijbrandij Sytse
Director · Officer · Ten-percent owner · GTLB
As of 2026-09-16, Sijbrandij Sytse has 98 Form 4 transactions on record across 1 company — 38 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 June in multiple years since 2025 — a recurring calendar cadence, more consistent with scheduled activity than a one-off decision.
Reconstructed holdings
- Direct $0
- Indirect $726.8M
| GTLB | indirect | 14,902,051 sh | $726.8M |
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 |
|---|---|---|---|---|---|---|---|
| 2026-06-15 | GTLB | Sale | 102,635 @ $28.39 | $2.9M | −0.7% of holding | 14,915,616 | Form 4 |
| 2026-06-15 | GTLB | Sale | 13,565 @ $28.83 | $391K | −0.1% of holding | 14,902,051 | Form 4 |
| 2026-05-18 | GTLB | Sale | 105,408 @ $24.93 | $2.6M | −0.7% of holding | 15,018,251 | Form 4 |
| 2026-05-18 | GTLB | Sale | 10,792 @ $24.09 | $260K | −0.1% of holding | 15,123,659 | Form 4 |
| 2026-04-15 | GTLB | Sale | 116,200 @ $20.77 | $2.4M | −100.0% of holding | 0 | Form 4 |
| 2026-02-17 | GTLB | Sale | 51,300 @ $28.36 | $1.5M | −94.5% of holding | 3,000 | Form 4 |
| 2026-02-17 | GTLB | Sale | 3,000 @ $29.18 | $88K | −100.0% of holding | 0 | Form 4 |
| 2026-01-14 | GTLB | Sale | 44,249 @ $35.85 | $1.6M | −81.5% of holding | 10,051 | Form 4 |
| 2026-01-14 | GTLB | Sale | 10,051 @ $36.43 | $366K | −100.0% of holding | 0 | Form 4 |
| 2025-12-15 | GTLB | Sale | 53,600 @ $38.94 | $2.1M | −98.7% of holding | 700 | Form 4 |
| 2025-12-15 | GTLB | Sale | 700 @ $39.60 | $28K | −100.0% of holding | 0 | Form 4 |
| 2025-11-17 | GTLB | Sale | 73,941 @ $42.98 | $3.2M | −68.1% of holding | 34,659 | Form 4 |
| 2025-11-17 | GTLB | Sale | 34,659 @ $43.59 | $1.5M | −100.0% of holding | 0 | Form 4 |
| 2025-10-15 | GTLB | Sale | 76,892 @ $44.10 | $3.4M | −70.8% of holding | 31,708 | Form 4 |
| 2025-10-15 | GTLB | Sale | 31,708 @ $44.75 | $1.4M | −100.0% of holding | 0 | Form 4 |
| 2025-09-15 | GTLB | Sale | 79,474 @ $50.02 | $4.0M | −73.2% of holding | 29,126 | Form 4 |
| 2025-09-15 | GTLB | Sale | 29,126 @ $50.45 | $1.5M | −100.0% of holding | 0 | Form 4 |
| 2025-08-18 | GTLB | Sale | 69,929 @ $45.47 | $3.2M | −91.6% of holding | 6,413 | Form 4 |
| 2025-08-18 | GTLB | Sale | 32,258 @ $44.32 | $1.4M | −29.7% of holding | 76,342 | Form 4 |
| 2025-08-18 | GTLB | Sale | 6,413 @ $45.98 | $295K | −100.0% of holding | 0 | Form 4 |
| 2025-07-15 | GTLB | Sale | 96,084 @ $43.24 | $4.2M | −88.5% of holding | 12,516 | Form 4 |
| 2025-07-15 | GTLB | Sale | 12,516 @ $44.06 | $551K | −100.0% of holding | 0 | Form 4 |
| 2025-06-16 | GTLB | Sale | 84,608 @ $41.25 | $3.5M | −77.9% of holding | 23,992 | Form 4 |
| 2025-06-16 | GTLB | Sale | 23,992 @ $42.11 | $1.0M | −100.0% of holding | 0 | Form 4 |
| 2025-05-14 | GTLB | Sale | 91,177 @ $52.92 | $4.8M | −84.0% of holding | 17,423 | Form 4 |
| 2025-05-14 | GTLB | Sale | 17,423 @ $53.58 | $934K | −100.0% of holding | 0 | Form 4 |
| 2025-04-15 | GTLB | Sale | 108,600 @ $42.87 | $4.7M | −100.0% of holding | 0 | Form 4 |
| 2025-03-17 | GTLB | Sale | 39,089 @ $51.79 | $2.0M | −69.8% of holding | 16,911 | Form 4 |
| 2025-03-17 | GTLB | Sale | 16,911 @ $52.32 | $885K | −100.0% of holding | 0 | Form 4 |
| 2025-02-18 | GTLB | Sale | 35,000 @ $70.66 | $2.5M | −54.7% of holding | 28,959 | Form 4 |
| 2025-02-18 | GTLB | Sale | 28,959 @ $71.37 | $2.1M | −100.0% of holding | 0 | Form 4 |
| 2025-02-18 | GTLB | Sale | 15,941 @ $69.68 | $1.1M | −20.0% of holding | 63,959 | Form 4 |
| 2025-02-18 | GTLB | Sale | 4,100 @ $68.42 | $281K | −4.9% of holding | 79,900 | Form 4 |
| 2025-01-15 | GTLB | Sale | 44,663 @ $62.68 | $2.8M | −53.2% of holding | 39,337 | Form 4 |
| 2025-01-15 | GTLB | Sale | 39,337 @ $63.35 | $2.5M | −100.0% of holding | 0 | Form 4 |
| 2024-12-17 | GTLB | Sale | 28,000 @ $60.21 | $1.7M | −100.0% of holding | 0 | Form 4 |
| 2024-12-16 | GTLB | Sale | 49,391 @ $58.86 | $2.9M | −88.2% of holding | 6,609 | Form 4 |
| 2024-12-16 | GTLB | Sale | 6,609 @ $59.27 | $392K | −100.0% of holding | 0 | Form 4 |
60 award / exercise / gift records — not counted as purchases
| Date | Company | Action | Shares | Owned after | Filing |
|---|---|---|---|---|---|
| 2026-05-14 | GTLB | Conversion | 15,134,451 | 15,134,451 | Form 4 |
| 2026-05-14 | GTLB | Conversion | 15,134,451 | 0 | Form 4 |
| 2026-05-14 | GTLB | Conversion | 15,134,451 | 0 | Form 4 |
| 2026-04-15 | GTLB | Conversion | 116,200 | 116,200 | Form 4 |
| 2026-04-15 | GTLB | Conversion | 116,200 | 15,134,451 | Form 4 |
| 2026-04-15 | GTLB | Conversion | 116,200 | 15,134,451 | Form 4 |
| 2026-02-17 | GTLB | Conversion | 54,300 | 54,300 | Form 4 |
| 2026-02-17 | GTLB | Conversion | 54,300 | 15,250,651 | Form 4 |
| 2026-02-17 | GTLB | Conversion | 54,300 | 15,250,651 | Form 4 |
| 2026-01-14 | GTLB | Conversion | 54,300 | 54,300 | Form 4 |
| 2026-01-14 | GTLB | Conversion | 54,300 | 15,304,951 | Form 4 |
| 2026-01-14 | GTLB | Conversion | 54,300 | 15,304,951 | Form 4 |
| 2025-12-15 | GTLB | Conversion | 54,300 | 54,300 | Form 4 |
| 2025-12-15 | GTLB | Conversion | 54,300 | 15,359,251 | Form 4 |
| 2025-12-15 | GTLB | Conversion | 54,300 | 15,359,251 | Form 4 |
| 2025-12-10 | GTLB | Gift | 311,721 | 15,413,551 | Form 4 |
| 2025-12-10 | GTLB | Gift | 311,721 | 15,413,551 | Form 4 |
| 2025-11-17 | GTLB | Conversion | 108,600 | 108,600 | Form 4 |
| 2025-11-17 | GTLB | Conversion | 108,600 | 15,725,272 | Form 4 |
| 2025-11-17 | GTLB | Conversion | 108,600 | 15,725,272 | Form 4 |
| 2025-10-15 | GTLB | Conversion | 108,600 | 108,600 | Form 4 |
| 2025-10-15 | GTLB | Conversion | 108,600 | 15,833,872 | Form 4 |
| 2025-10-15 | GTLB | Conversion | 108,600 | 15,833,872 | Form 4 |
| 2025-09-15 | GTLB | Conversion | 108,600 | 108,600 | Form 4 |
| 2025-09-15 | GTLB | Conversion | 108,600 | 15,942,472 | Form 4 |
| 2025-09-15 | GTLB | Conversion | 108,600 | 15,942,472 | Form 4 |
| 2025-08-18 | GTLB | Conversion | 108,600 | 108,600 | Form 4 |
| 2025-08-18 | GTLB | Conversion | 108,600 | 16,051,072 | Form 4 |
| 2025-08-18 | GTLB | Conversion | 108,600 | 16,051,072 | Form 4 |
| 2025-07-15 | GTLB | Conversion | 108,600 | 108,600 | Form 4 |
| 2025-07-15 | GTLB | Conversion | 108,600 | 16,159,672 | Form 4 |
| 2025-07-15 | GTLB | Conversion | 108,600 | 16,159,672 | Form 4 |
| 2025-06-16 | GTLB | Conversion | 108,600 | 108,600 | Form 4 |
| 2025-06-16 | GTLB | Conversion | 108,600 | 16,268,272 | Form 4 |
| 2025-06-16 | GTLB | Conversion | 108,600 | 16,268,272 | Form 4 |
| 2025-05-14 | GTLB | Conversion | 108,600 | 108,600 | Form 4 |
| 2025-05-14 | GTLB | Conversion | 108,600 | 16,376,872 | Form 4 |
| 2025-05-14 | GTLB | Conversion | 108,600 | 16,376,872 | Form 4 |
| 2025-04-15 | GTLB | Conversion | 108,600 | 108,600 | Form 4 |
| 2025-04-15 | GTLB | Conversion | 108,600 | 16,485,472 | 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.