Thomas S. Bremner - SEC Form 4 Insider Trading Activity
Summary
Updated Aug 3, 2026
Thomas S. Bremner has filed 1 SEC Form 4 filing across 1 company in the last 90 days - buying. Lifetime open-market purchases: $2.50M. Historical track record: 4/5 stars across 6 tracked purchases.
Profile
Thomas S. Bremner is a corporate insider at BillionToOne, Inc. (BLLN). Bremner has reported 4 insider filings with the SEC since 2025. The most recent filing was in June 2026.
| Role | Insider |
|---|---|
| Notability | 20/100 |
Board memberships
- BillionToOne, Inc.
Track Record
InsiderAlpha computes a forward-return-based score for every insider with enough Form 4 purchase history. The metrics below reflect realised performance after each tracked open-market purchase.
| InsiderAlpha rating | ★★★★☆ (4/5) |
|---|---|
| Total purchases tracked | 6 |
| Purchases with forward-return data | 6 |
| 30-day win rate | 100% |
| 90-day win rate | 0% |
| Avg 5-day return | +1.77% |
| Avg 30-day return | +4.63% |
| Avg 90-day return | -14.88% |
| Best 30-day return | +4.63% |
Trading Pattern
InsiderAlpha's records for Thomas S. Bremner go back to 2025: 2 primary Form 4 filings, an average of 1.0 per year. The typical open-market purchase is $417K (6 buys totaling $2.50M). The largest single buy on record is $1.07M of BLLN in 2025. 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.
Career & Filing History
Every role Thomas S. Bremner has reported on a Form 4, reconstructed from the filings themselves - reporting insiders must state their relationship to the issuer (officer title, director seat, or 10% ownership) on every filing.
- Insider at BillionToOne, Inc. (BLLN) - 2 filings, 2025 to 2026
Recent Transactions
| Date | Ticker | Company | Code | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 2026-06-12 | BLLN | BillionToOne, Inc. | A - Grant or award | 3.0K | $0.00 | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | P - Open-market purchase | 17.8K | $60.00 | $1.07M |
| 2025-11-10 | BLLN | BillionToOne, Inc. | P - Open-market purchase | 6.9K | $60.00 | $412K |
| 2025-11-10 | BLLN | BillionToOne, Inc. | P - Open-market purchase | 5.4K | $60.00 | $327K |
| 2025-11-10 | BLLN | BillionToOne, Inc. | P - Open-market purchase | 3.5K | $60.00 | $208K |
| 2025-11-10 | BLLN | BillionToOne, Inc. | P - Open-market purchase | 4.1K | $60.00 | $245K |
| 2025-11-10 | BLLN | BillionToOne, Inc. | P - Open-market purchase | 4.0K | $60.00 | $241K |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 277.5K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 675.4K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 240.1K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 269.9K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 176.3K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 155.7K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 152.4K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 8.3K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 277.5K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 675.4K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 240.1K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 269.9K | - | |
| 2025-11-10 | BLLN | BillionToOne, Inc. | J - Other acquisition / disposition | 176.3K | - |
Companies - Last 90 Days
- BillionToOne, Inc. (BLLN) - 1 filing, last 2026-06-12
Other Insiders Active in the Same Stocks
Insiders who reported open-market trades at the companies Thomas S. Bremner has recently filed at. Multiple unrelated insiders buying the same stock within a short window - cluster buying - has historically been one of the strongest Form 4 signals.
- Oguzhan Atay - $10.10M of BLLN open-market activity in the last 12 months
- David Tsao - $4.60M of BLLN open-market activity in the last 12 months
- Nancy Joann Johnson - $3.74M of BLLN open-market activity in the last 12 months
- Shan Riku Sakakibara - $2.67M of BLLN open-market activity in the last 12 months
- Bosch John Roderick Ten - $1.04M of BLLN open-market activity in the last 12 months
- Akshay Rai - $150K of BLLN open-market activity in the last 12 months
More Notable Insiders
Other corporate insiders with significant SEC Form 4 track records on InsiderAlpha:
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- Viking Cake BR, LLC
Frequently Asked Questions
Who is Thomas S. Bremner?
Thomas S. Bremner is a corporate insider at BillionToOne, Inc. (BLLN). Bremner has reported 4 insider filings with the SEC since 2025. The most recent filing was in June 2026.…
How many SEC Form 4 filings has Thomas S. Bremner submitted recently?
1 primary Form 4 filing in the last 90 days, covering 1 company.
Has Thomas S. Bremner been buying or selling stock?
Recorded transactions: 6 open-market purchases ($2.50M) and 0 open-market sales across all tracked filings.
How accurate is Thomas S. Bremner's historical track record?
Across 6 tracked purchases, Thomas S. Bremner averaged +4.6% avg 30-day return with a 100% 30-day win rate. InsiderAlpha rates the track record at 4/5 stars.
Where can I see all of Thomas S. Bremner'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.
Learn More
Open the live Thomas S. Bremner profile on InsiderAlpha for real-time alerts, AI-scored trade ideas, and full transaction history.