SEC Form 4
BillionToOne, Inc. (BLLN) insider trading
In the 12 months to Oct 26, 2026, 6 BLLN insiders reported open-market sales of $51.3M across 34 filings; no open-market purchases were filed.
Latest filing · Last 12 months · Source: SEC EDGAR · How we count
- Open-market sales
- $51.3M
- 34 filings · 6 insiders
- Open-market purchases
- $0
- 0 filings
- Pre-arranged sales (10b5-1)
- 34 of 34
- All $51.3M sold was pre-arranged
Who traded BLLN, and when
- Sale
- Sale, pre-arranged (10b5-1)
BLLN daily close from Nov 6, 2025 to Oct 26, 2026, between $64.03 and $149.97, last $111.18. 34 sale and 0 purchase filings by 6 insiders, marked at their filing dates. Oguzhan Atay, Officer (see filing) → Chairman and CEO: sold $25.9M across 9 filings, first filed Jun 10, 2026, last Oct 16, 2026. David Tsao, Chief Technology Officer: sold $11.0M across 7 filings, first filed Jun 17, 2026, last Oct 7, 2026. Thomas P. Lynch, Officer (see filing): sold $5.9M across 2 filings, first filed Sep 10, 2026, last Sep 21, 2026. Nancy JoAnn Johnson, Officer (see filing): sold $3.3M across 3 filings, first filed Jun 10, 2026, last Jul 20, 2026. Shan Riku Sakakibara, Chief Product Officer: sold $3.2M across 4 filings, first filed Jun 10, 2026, last Aug 4, 2026. Bosch John Roderick ten, Officer (see filing) → SVP of Laboratory Operations: sold $2.0M across 9 filings, first filed Jun 17, 2026, last Oct 7, 2026.
Largest mark · tap a row for others
Oguzhan Atay · Chairman and CEO
Filing 1 of 2 within a week · $8,499,312 total
Sale $6,167,960
45,000 shares at $137.07 avg
Filed Aug 5, 2026 · traded Aug 3
Pre-arranged (10b5-1) · close on filing date $149.97
Oguzhan Atay · Officer (see filing) → Chairman and CEO
Officer (see filing) → Chairman and CEO
$25.9M soldDavid Tsao · Chief Technology Officer
Chief Technology Officer
$11.0M soldThomas P. Lynch · Officer (see filing)
Officer (see filing)
$5.9M soldNancy JoAnn Johnson · Officer (see filing)
Officer (see filing)
$3.3M soldShan Riku Sakakibara · Chief Product Officer
Chief Product Officer
$3.2M soldBosch John Roderick ten · Officer (see filing) → SVP of Laboratory Operations
Officer (see filing) → SVP of Laboratory Operations
$2.0M soldOpen-market trades
34 filings in the last 12 months| Insider | Role | Sold | Bought | Filings | Pre-arranged (10b5-1) | Last filed |
|---|---|---|---|---|---|---|
| Oguzhan Atay | Officer (see filing) → Chairman and CEO | $25.9M | — | 9 | 100% of sales | |
| David Tsao | Chief Technology Officer | $11.0M | — | 7 | 100% of sales | |
| Thomas P. Lynch | Officer (see filing) | $5.9M | — | 2 | 100% of sales | |
| Nancy JoAnn Johnson | Officer (see filing) | $3.3M | — | 3 | 100% of sales | |
| Shan Riku Sakakibara | Chief Product Officer | $3.2M | — | 4 | 100% of sales | |
| Bosch John Roderick ten | Officer (see filing) → SVP of Laboratory Operations | $2.0M | — | 9 | 100% of sales |
| Filed | Insider | Type | Shares | Avg price | Value | Held after | Source |
|---|---|---|---|---|---|---|---|
traded | Oguzhan Atay Chairman and CEO | SalePre-arranged (10b5-1) | 11,000 | $99.14 | $1.1M | Multiple accounts | |
traded | Oguzhan Atay Chairman and CEO | SalePre-arranged (10b5-1) | 19,334 | $94.31 | $1.8M | Multiple accounts | |
traded | Bosch John Roderick ten SVP of Laboratory Operations | SalePre-arranged (10b5-1) | 2,834 | $105.15 | $298.0K | 19,385 | |
traded | David Tsao Chief Technology Officer | SalePre-arranged (10b5-1) | 20,000 | $108.15 | $2.2M | 13,941 | |
traded | Oguzhan Atay Chairman and CEO | SalePre-arranged (10b5-1) | 10,999 | $120.64 | $1.3M | Multiple accounts | |
traded | Bosch John Roderick ten SVP of Laboratory Operations | SalePre-arranged (10b5-1) | 1,416 | $120.00 | $169.9K | 22,219 | |
traded | David Tsao Chief Technology Officer | SalePre-arranged (10b5-1) | 3,333 | $125.00 | $416.6K | 1,000 | |
traded | Bosch John Roderick ten SVP of Laboratory Operations | SalePre-arranged (10b5-1) | 1,416 | $106.61 | $151.0K | 23,635 | |
traded | Thomas P. Lynch Officer (see filing) | SalePre-arranged (10b5-1) | 35,112 | $110.33 | $3.9M | 6,540 | |
traded | Oguzhan Atay Chairman and CEO | SalePre-arranged (10b5-1) | 30,331 | $99.91 | $3.0M | Multiple accounts | |
traded | Bosch John Roderick ten SVP of Laboratory Operations | SalePre-arranged (10b5-1) | 1,416 | $97.54 | $138.1K | 25,051 | |
traded | David Tsao Chief Technology Officer | SalePre-arranged (10b5-1) | 20,000 | $98.77 | $2.0M | 1,000 | |
traded | Thomas P. Lynch Officer (see filing) | SalePre-arranged (10b5-1) | 20,000 | $99.99 | $2.0M | 4,026 | |
traded | Bosch John Roderick ten SVP of Laboratory Operations | SalePre-arranged (10b5-1) | 1,417 | $100.00 | $141.7K | 26,467 | |
traded | David Tsao Chief Technology Officer | SalePre-arranged (10b5-1) | 10,000 | $100.00 | $1.0M | 1,000 | |
traded | David Tsao Chief Technology Officer | SalePre-arranged (10b5-1) | 10,000 | $92.86 | $928.6K | 1,000 | |
traded | Bosch John Roderick ten SVP of Laboratory Operations | SalePre-arranged (10b5-1) | 1,417 | $92.86 | $131.6K | 27,884 | |
traded | Oguzhan Atay Chairman and CEO | SalePre-arranged (10b5-1) | 15,539 | $150.03 | $2.3M | 0 | |
traded | Oguzhan Atay Chairman and CEO | SalePre-arranged (10b5-1) | 45,000 | $137.07 | $6.2M | Multiple accounts | |
traded | Shan Riku Sakakibara Chief Product Officer | SalePre-arranged (10b5-1) | 4,000 | $140.21 | $560.8K | 200,000 | |
traded | Nancy JoAnn Johnson Officer (see filing) | SalePre-arranged (10b5-1) | 14,199 | $128.29 | $1.8M | 13,407 | |
traded | Bosch John Roderick ten SVP of Laboratory Operations | SalePre-arranged (10b5-1) | 4,251 | $125.46 | $533.3K | 32,135 | |
traded | David Tsao Chief Technology Officer | SalePre-arranged (10b5-1) | 20,000 | $124.88 | $2.5M | 19,898 | |
traded | Shan Riku Sakakibara Chief Product Officer | SalePre-arranged (10b5-1) | 8,000 | $125.00 | $1.0M | 208,000 | |
traded | Oguzhan Atay Chairman and CEO | SalePre-arranged (10b5-1) | 12,500 | $126.10 | $1.6M | 3,009 | |
traded | Oguzhan Atay Chairman and CEO | SalePre-arranged (10b5-1) | 38,750 | $122.05 | $4.7M | Multiple accounts | |
traded | Nancy JoAnn Johnson Officer (see filing) | SalePre-arranged (10b5-1) | 801 | $124.91 | $100.1K | 21,099 | |
traded | Bosch John Roderick ten SVP of Laboratory Operations | SalePre-arranged (10b5-1) | 1,416 | $120.00 | $169.9K | 33,552 | |
traded | Shan Riku Sakakibara Chief Product Officer | SalePre-arranged (10b5-1) | 8,000 | $110.00 | $880.0K | 212,000 | |
traded | Bosch John Roderick ten Officer (see filing) | SalePre-arranged (10b5-1) | 2,832 | $101.47 | $287.4K | 34,968 | |
traded | David Tsao Chief Technology Officer | SalePre-arranged (10b5-1) | 20,000 | $102.27 | $2.0M | 3,961 | |
traded | Nancy JoAnn Johnson Officer (see filing) | SalePre-arranged (10b5-1) | 14,000 | $100.18 | $1.4M | 27,816 | |
traded | Shan Riku Sakakibara Chief Product Officer | SalePre-arranged (10b5-1) | 8,000 | $98.23 | $785.8K | 216,000 | |
traded | Oguzhan Atay Officer (see filing) | SalePre-arranged (10b5-1) | 38,750 | $97.84 | $3.8M | Multiple accounts |
GET /stocks/filings/vX/form-4?tickers=BLLN&filing_date.gte=2025-10-26&sort=filing_date.desc&limit=500{
"status": "OK",
"results": [
{
"tickers": [
"BLLN"
],
"issuer_cik": "0002070849",
"owner_cik": "0002088549",
"accession_number": "0002088549-26-000015",
"form_type": "4",
"filing_date": "2026-10-16",
"period_of_report": "2026-10-14",
"issuer_name": "BillionToOne, Inc.",
"issuer_trading_symbol": "BLLN",
"owner_name": "Atay Oguzhan",
"is_director": true,
"is_officer": true,
"is_ten_percent_owner": false,
"is_other": false,
"officer_title": "Chairman and CEO",
"security_type": "non_derivative",
"record_type": "transaction",
"security_title": "Class A Common Stock",
"transaction_timeliness": "O",
"aff_10b5_one": true,
"transaction_date": "2026-10-14",
"transaction_code": "S",
"equity_swap_involved": false,
"transaction_shares": 3083,
"transaction_price_per_share": 98.3198,
"transaction_acquired_disposed": "D",
"shares_owned_following_transaction": 100,
"transaction_value": 303119.9434,
"not_subject_to_section_16": false,
"direct_or_indirect": "D",
"footnotes": [
{
"id": "F1",
"description": "The transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 5, 2026."
},
{
"id": "F2",
"description": "The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $98.000 to $98.990 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."
}
]
},
{
"tickers": [
"BLLN"
],
"issuer_cik": "0002070849",
"owner_cik": "0002088549",
"accession_number": "0002088549-26-000015",
"form_type": "4",
"filing_date": "2026-10-16",
"period_of_report": "2026-10-14",
"issuer_name": "BillionToOne, Inc.",
"issuer_trading_symbol": "BLLN",
"owner_name": "Atay Oguzhan",
"is_director": true,
"is_officer": true,
"is_ten_percent_owner": false,
"is_other": false,
"officer_title": "Chairman and CEO",
"security_type": "non_derivative",
"record_type": "transaction",
"security_title": "Class A Common Stock",
"transaction_timeliness": "O",
"aff_10b5_one": true,
"transaction_date": "2026-10-15",
"transaction_code": "S",
"equity_swap_involved": false,
"transaction_shares": 900,
"transaction_price_per_share": 98.4328,
"transaction_acquired_disposed": "D",
"shares_owned_following_transaction": 4250,
"transaction_value": 88589.52,
"not_subject_to_section_16": false,
"direct_or_indirect": "D",
"footnotes": [
{
"id": "F1",
"description": "The transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 5, 2026."
},
{
"id": "F3",
"description": "The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $98.000 to $98.770 per share, inclusive. The holder undertakes to provide, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."
}
]
}
]
}
// trimmed to 2 resultsThe response includes every Form 4 record; this page keeps open-market purchases and sales on common stock and removes duplicate joint-filer rows.
Other insider activity (not market trades) · 137 records
- Option exercises41 records
- Grants and awards6 records
- Gifts4 records
- Other86 records
Reported on Form 4 but not purchases or sales in the market, so not counted in the totals above.
How to read this page
- Open-market purchase or sale
- A buy or sell of the company's stock at market price. Grants, option exercises, shares withheld for tax, gifts and employee stock plan purchases are listed separately and not counted.
- Pre-arranged (10b5-1)
- The insider marked the filing as made under a trading plan set up in advance (SEC Rule 10b5-1). The mark covers the whole filing, and an unmarked filing may still be under a plan.
- Role
- The title on each filing. Someone whose title changed shows more than one.
- Filing date
- Insiders have two business days to report a trade. Totals and the chart use the filing date, when the trade became public.
Frequently asked questions
Has BillionToOne, Inc.'s CEO sold stock?
Yes. Oguzhan Atay (CEO) sold 183,453 shares ($22.1M) between Jul 2026 and Oct 2026, all under a pre-arranged 10b5-1 plan.
How current is BLLN’s insider data?
These are BLLN Form 4 filings from the last year, refreshed daily. The Massive Form 4 API has the full, continuously updated record.
What counts as an open-market buy or sell?
Only purchases and sales at the market price. Option exercises, grants, gifts, and shares withheld for taxes are reported on Form 4 but are left out of the buy and sell totals.
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