STOCK TITAN

BillionToOne (BLLN) insider trades shares, exercises options and gifts stock

Filing Impact
(Very High)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

BillionToOne, Inc. director and officer Atay Oguzhan reported multiple transactions in the company’s Class A and Class B common stock. On June 8, 2026, he acquired a total of 36,250 shares of Class A common stock through option exercises and conversion of Class B shares at prices from $0.00 to $2.80 per share.

That same day, 38,750 shares of Class A common stock were sold in open-market transactions at weighted-average prices ranging from about $94.30 to $100.87, including sales of shares held by his spouse. On June 9, 2026, he made a bona fide gift of 10,000 Class A shares. The transactions were effected under a Rule 10b5-1 trading plan adopted on March 6, 2026.

Positive

  • None.

Negative

  • None.
Insider Atay Oguzhan
Role See Remarks
Sold 38,750 shs ($3.79M)
Type Security Shares Price Value
Gift Class A Common Stock 10,000 $0.00 --
Exercise Stock Option (right to buy) 20,000 $2.80 $56K
Exercise Stock Option (right to buy) 6,250 $2.80 $18K
Conversion Class B Common Stock 10,000 $0.00 --
Exercise Class A Common Stock 20,000 $2.80 $56K
Exercise Class A Common Stock 6,250 $2.80 $18K
Sale Class A Common Stock 79 $100.87 $8K
Sale Class A Common Stock 5,466 $94.7627 $518K
Sale Class A Common Stock 1,856 $95.5898 $177K
Sale Class A Common Stock 4,372 $96.8921 $424K
Sale Class A Common Stock 4,066 $98.1209 $399K
Sale Class A Common Stock 3,605 $99.063 $357K
Sale Class A Common Stock 556 $99.9688 $56K
Sale Class A Common Stock 6,250 $100.00 $625K
Conversion Class A Common Stock 10,000 $0.00 --
Sale Class A Common Stock 6,250 $96.45 $603K
Sale Class A Common Stock 6,250 $100.00 $625K
Holdings After Transaction: Class A Common Stock — 0 shares (Direct, null); Stock Option (right to buy) — 620,000 shares (Direct, null); Class B Common Stock — 2,217,542 shares (Direct, null); Class A Common Stock — 193,750 shares (Indirect, By spouse)
Footnotes (1)
  1. 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. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $94.300 to $95.280 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. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $95.320 to $96.225 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. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $96.530 to $97.2113 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. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $97.560 to $98.5428 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. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $98.560 to $99.550 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. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.640 to $100.540 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. These shares of Class B common stock were converted at a 1:1 ratio for shares of Class A common stock at the option of the holder. Represents shares held by the Reporting Person's spouse. The options are fully vested and exercisable. Each share of Class B Common Stock is convertible into one share of Class A common stock at the option of the holder. Class B common stock will convert automatically on a one-for-one basis into shares of the Issuer's Class A common stock upon the earliest of (i) seven years from the date of filing of the amended and restated certificate of incorporation, in connection with the Offering and (ii) the date specified by a vote of the holders of Class B common stock representing a majority of the outstanding shares of Class B common stock.
Shares sold 38,750 shares Class A common stock open-market sales on June 8, 2026
Shares acquired via exercise/conversion 36,250 shares Class A shares from option exercises and Class B conversion on June 8, 2026
Option exercise price $2.80 per share Stock options exercised into Class A common stock
Sale price range $94.300–$100.870 per share Weighted-average price ranges for grouped open-market sales
Gifted shares 10,000 shares Bona fide gift of Class A common stock on June 9, 2026
10b5-1 plan adoption date March 6, 2026 Plan governing reported transactions
Converted Class B shares 10,000 shares Class B common stock converted 1:1 into Class A
Remaining stock options 620,000 options Stock Option (right to buy) position after June 8, 2026 exercise
Rule 10b5-1 trading plan regulatory
"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."
A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.
bona fide gift financial
"transaction_code_description": "Bona fide gift""
A bona fide gift is a genuine, voluntary transfer of money, property, or benefits from one party to another made without expectation of repayment, services, or hidden conditions. Investors care because such gifts can affect company disclosures, related‑party transaction rules, tax treatment, and perceived conflicts of interest; think of it like someone giving you a present with no strings attached — but on a corporate scale, auditors and regulators need to verify it really is unconditional.
weighted average price financial
"The reported price in Column 4 is a weighted average price."
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
Class B common stock financial
"These shares of Class B common stock were converted at a 1:1 ratio for shares of Class A common stock"
A class B common stock is one of multiple types of a company’s ordinary shares that carries specific rights—often different voting power or dividend priority—compared with other classes. For investors it matters because those differences affect how much influence you have over company decisions, the income you might receive, and how freely the shares trade; think of it like owning a car with different keys: some keys let you start the engine and open the trunk, others only unlock the door.
Stock Option (right to buy) financial
"security_title": "Stock Option (right to buy)""
open market or private transaction financial
"transaction_code_description": "Sale in open market or private transaction""
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SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
X
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Atay Oguzhan

(Last)(First)(Middle)
C/O BILLIONTOONE, INC.
1035 O'BRIEN DRIVE

(Street)
MENLO PARK CALIFORNIA 94025

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
BillionToOne, Inc. [ BLLN ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
XOfficer (give title below)Other (specify below)
See Remarks
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
06/08/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Class A Common Stock06/08/2026M(1)20,000A$2.820,000D
Class A Common Stock06/08/2026M(1)6,250A$2.826,250D
Class A Common Stock06/08/2026S(1)79D$100.8726,171D
Class A Common Stock06/08/2026S(1)5,466D$94.7627(2)20,705D
Class A Common Stock06/08/2026S(1)1,856D$95.5898(3)18,849D
Class A Common Stock06/08/2026S(1)4,372D$96.8921(4)14,477D
Class A Common Stock06/08/2026S(1)4,066D$98.1209(5)10,411D
Class A Common Stock06/08/2026S(1)3,605D$99.063(6)6,806D
Class A Common Stock06/08/2026S(1)556D$99.9688(7)6,250D
Class A Common Stock06/08/2026S(1)6,250D$1000D
Class A Common Stock06/08/2026C(8)10,000A$0(8)10,000D
Class A Common Stock06/09/2026G10,000D$00D
Class A Common Stock06/08/2026S(1)6,250D$96.45193,750IBy spouse(9)
Class A Common Stock06/08/2026S(1)6,250D$100187,500IBy spouse(9)
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Stock Option (right to buy)$2.806/08/2026M20,000 (10)06/07/2031Class A Common Stock20,000$2.8620,000D
Stock Option (right to buy)$2.806/08/2026M6,250 (10)06/07/2031Class A Common Stock6,250$2.8613,750D
Class B Common Stock(8)(11)06/08/2026C10,000 (11) (11)Class A Common Stock10,000$0(8)2,217,542D
Explanation of Responses:
1. 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.
2. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $94.300 to $95.280 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.
3. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $95.320 to $96.225 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.
4. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $96.530 to $97.2113 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.
5. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $97.560 to $98.5428 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.
6. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $98.560 to $99.550 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.
7. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.640 to $100.540 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.
8. These shares of Class B common stock were converted at a 1:1 ratio for shares of Class A common stock at the option of the holder.
9. Represents shares held by the Reporting Person's spouse.
10. The options are fully vested and exercisable.
11. Each share of Class B Common Stock is convertible into one share of Class A common stock at the option of the holder. Class B common stock will convert automatically on a one-for-one basis into shares of the Issuer's Class A common stock upon the earliest of (i) seven years from the date of filing of the amended and restated certificate of incorporation, in connection with the Offering and (ii) the date specified by a vote of the holders of Class B common stock representing a majority of the outstanding shares of Class B common stock.
Remarks:
Chairman and Chief Executive Officer
/s/ Thomas P. Lynch, Attorney-in-Fact06/10/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transactions did BLLN’s Atay Oguzhan report in this Form 4?

Atay Oguzhan reported option exercises, a Class B to Class A share conversion, open-market sales, and a stock gift. He acquired 36,250 Class A shares via exercises and conversion, sold 38,750 Class A shares, and gifted 10,000 Class A shares across the reported dates.

How many BillionToOne (BLLN) shares did the insider sell, and at what prices?

Reported transactions show 38,750 shares of BLLN Class A common stock sold in open-market trades. Weighted-average prices ranged roughly from $94.30 to $100.87 per share, with detailed price ranges disclosed for separate trade groups in the accompanying footnotes to the filing.

What options or conversions did the BLLN insider execute in this filing?

Oguzhan exercised stock options and converted Class B shares into Class A shares. In total, 36,250 Class A shares were acquired through these derivative exercises and conversions at prices between $0.00 and $2.80 per share, reflecting a shift from derivative holdings into direct common stock.

Was any of the BLLN stock owned indirectly, such as by a spouse?

Yes. Some Class A common stock was held indirectly through the reporting person’s spouse. The filing notes that certain open‑market sales on June 8, 2026 involved shares "held by the Reporting Person's spouse," clarifying that these transactions relate to indirect family holdings.

Did the BLLN insider make any stock gifts in the reported period?

The filing reports a bona fide gift of 10,000 shares of Class A common stock. This gift transaction, coded "G," occurred on June 9, 2026 at a reported price of $0.00 per share, reflecting a non‑market, no‑consideration transfer of shares.

Were the BLLN insider’s share sales made under a Rule 10b5-1 plan?

Yes. A footnote states the transactions were effected under a Rule 10b5-1 trading plan adopted on March 6, 2026. Such pre-arranged plans automate trading according to preset instructions, helping separate routine portfolio management from discretionary timing decisions.