Key facts
- This page summarizes Oguzhan Atay's Form 4 filing for BillionToOne, Inc. (BLLN).
- 32 reported transactions and 2 derivative rows are listed below.
- Accepted by SEC: 08 Jul 2026, 19:06.
Oguzhan Atay - 06 Jul 2026 Form 4 Insider Report for BillionToOne, Inc. (BLLN)
- Reporting relationship
- Chairman and CEO, Director
- Issuer ticker
- BLLN
- Reported as of
- 06 Jul 2026
- Net transaction value
- -$4,729,379
- SEC form
- 4
- Accepted by SEC
- 08 Jul 2026, 19:06:42 UTC
- Prior SEC filing
- 10 Jun 2026
- Next SEC filing
- 13 Jul 2026
- Source filing
- View source filing
- Reporting owner signature
- /s/ Thomas P. Lynch, Attorney-in-Fact
Source evidence
Original filing metadata and source links for verification.
5 source fields
Reporting owner
1 detail
Key filing fact
Oguzhan Atay filed Form 4 for BillionToOne, Inc. (BLLN) on 08 Jul 2026.
Change
- Previous filing in this sequence was filed on 10 Jun 2026.
- Current net transaction value: -$4,729,379.
Research use
- This tells you what this filing adds before you inspect full transaction and derivative tables.
- You can trace every row back to the original SEC filing document.
Evidence
Filed on Form 4
View source filing
Ownership activity is grounded in SEC Form 4 disclosures.
Reporting Owners (1)
CIK 0002088549
Primary reporting owner
Atay Oguzhan
- Relationship
- Chairman and CEO, Director
- Address
- C/O BILLIONTOONE, INC., 1035 O'BRIEN DRIVE, MENLO PARK
- Signature
- /s/ Thomas P. Lynch, Attorney-in-Fact
- Signature date
- 08 Jul 2026
Reported non-derivative transactions
Shares, units, or other non-derivative securities reported in this filing.
BLLN
transaction
Class A Common Stock
Options Exercise
- Transaction value
- Shares
- +20,000
- Change %
- Price
- $2.80*
- Shares after
- 20,000
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1
BLLN
transaction
Class A Common Stock
Options Exercise
- Transaction value
- Shares
- +6,250
- Change %
- +31%
- Price
- $2.80*
- Shares after
- 26,250
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $156,402
- Shares
- -1,320
- Change %
- -5%
- Price
- $118.49
- Shares after
- 24,930
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F2
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $434,369
- Shares
- -3,639
- Change %
- -15%
- Price
- $119.36
- Shares after
- 21,291
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F3
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $220,567
- Shares
- -1,828
- Change %
- -8.6%
- Price
- $120.66
- Shares after
- 19,463
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F4
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $135,848
- Shares
- -1,115
- Change %
- -5.7%
- Price
- $121.84
- Shares after
- 18,348
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F5
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $765,873
- Shares
- -6,223
- Change %
- -34%
- Price
- $123.07
- Shares after
- 12,125
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F6
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $650,371
- Shares
- -5,253
- Change %
- -43%
- Price
- $123.81
- Shares after
- 6,872
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F7
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $77,510
- Shares
- -622
- Change %
- -9.1%
- Price
- $124.61
- Shares after
- 6,250
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F8
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $48,817
- Shares
- -412
- Change %
- -6.6%
- Price
- $118.49
- Shares after
- 5,838
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F2
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $135,837
- Shares
- -1,138
- Change %
- -19%
- Price
- $119.36
- Shares after
- 4,700
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F3
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $68,776
- Shares
- -570
- Change %
- -12%
- Price
- $120.66
- Shares after
- 4,130
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F4
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $42,521
- Shares
- -349
- Change %
- -8.5%
- Price
- $121.84
- Shares after
- 3,781
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F5
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $239,373
- Shares
- -1,945
- Change %
- -51%
- Price
- $123.07
- Shares after
- 1,836
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F6
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $203,295
- Shares
- -1,642
- Change %
- -89%
- Price
- $123.81
- Shares after
- 194
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F7
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $24,175
- Shares
- -194
- Change %
- -100%
- Price
- $124.61
- Shares after
- 0
- Date
- 06 Jul 2026
- Ownership
- Direct
- Footnotes
- F1, F8
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $122,847
- Shares
- -1,034
- Change %
- -0.55%
- Price
- $118.81
- Shares after
- 186,466
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F9, F10
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $70,728
- Shares
- -591
- Change %
- -0.32%
- Price
- $119.67
- Shares after
- 185,875
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F11
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $53,585
- Shares
- -444
- Change %
- -0.24%
- Price
- $120.69
- Shares after
- 185,431
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F12
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $71,663
- Shares
- -587
- Change %
- -0.32%
- Price
- $122.08
- Shares after
- 184,844
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F13
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $286,303
- Shares
- -2,323
- Change %
- -1.3%
- Price
- $123.25
- Shares after
- 182,521
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F14
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $151,459
- Shares
- -1,221
- Change %
- -0.67%
- Price
- $124.04
- Shares after
- 181,300
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F15
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $6,237
- Shares
- -50
- Change %
- -0.03%
- Price
- $124.74
- Shares after
- 181,250
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $122,847
- Shares
- -1,034
- Change %
- -0.57%
- Price
- $118.81
- Shares after
- 180,216
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F9, F10
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $70,728
- Shares
- -591
- Change %
- -0.33%
- Price
- $119.67
- Shares after
- 179,625
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F11
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $53,585
- Shares
- -444
- Change %
- -0.25%
- Price
- $120.69
- Shares after
- 179,181
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F12
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $71,542
- Shares
- -586
- Change %
- -0.33%
- Price
- $122.08
- Shares after
- 178,595
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F13
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $286,426
- Shares
- -2,324
- Change %
- -1.3%
- Price
- $123.25
- Shares after
- 176,271
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F14
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $151,459
- Shares
- -1,221
- Change %
- -0.69%
- Price
- $124.04
- Shares after
- 175,050
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10, F15
BLLN
transaction
Class A Common Stock
Sale
- Transaction value
- $6,237
- Shares
- -50
- Change %
- -0.03%
- Price
- $124.74
- Shares after
- 175,000
- Date
- 06 Jul 2026
- Ownership
- By spouse
- Footnotes
- F1, F10
Reported derivative securities
Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.
BLLN
transaction
Derivative
Stock Option (right to buy)
Options Exercise
- Transaction value
- Shares
- -20,000
- Change %
- -3.3%
- Price
- $2.80*
- Shares after
- 593,750
- Date
- 06 Jul 2026
- Ownership
- Direct
- Underlying class
- Class A Common Stock
- Underlying amount
- 20,000
- Exercise price
- $2.80
- Footnotes
- F16
BLLN
transaction
Derivative
Stock Option (right to buy)
Options Exercise
- Transaction value
- Shares
- -6,250
- Change %
- -1.1%
- Price
- $2.80*
- Shares after
- 587,500
- Date
- 06 Jul 2026
- Ownership
- Direct
- Underlying class
- Class A Common Stock
- Underlying amount
- 6,250
- Exercise price
- $2.80
- Footnotes
- F16
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Rule 10b5-1 trading plan
These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.
Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).
Explanation of responses 16 footnotes
Footnote F1
The transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2026.
Footnote F2
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.050 to $119.020 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.
Footnote F3
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.055 to $119.970 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.
Footnote F4
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $120.225 to $121.160 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.
Footnote F5
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.390 to $122.230 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.
Footnote F6
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $122.465 to $123.450 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.
Footnote F7
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $123.475 to $124.455 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.
Footnote F8
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $124.535 to $124.735 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.
Footnote F9
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.250 to $119.240 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.
Footnote F10
Represents shares held by the Reporting Person's spouse.
Footnote F11
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.305 to $120.2725 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.
Footnote F12
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $120.380 to $121.020 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.
Footnote F13
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.555 to $122.490 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.
Footnote F14
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $122.725 to $123.720 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.
Footnote F15
The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $123.740 to $124.735 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.
Footnote F16
The options are fully vested and exercisable.