BillionToOne SVP sells 1,416 shares in plan

BillionToOne, Inc. senior vice president of laboratory operations John Roderick ten Bosch reported an open-market sale of 1,416 shares of Class A Common Stock at $120.00 per share.

Rhea-AI Filing Summary

BillionToOne, Inc. senior vice president of laboratory operations John Roderick ten Bosch reported an open-market sale of 1,416 shares of Class A Common Stock at $120.00 per share. The transaction occurred on June 29, 2026 under a pre-arranged Rule 10b5-1 trading plan adopted on March 6, 2026, and he continues to hold 33,552 shares directly after the sale.

Insider Trade Summary 10b5-1

Net Seller: 1,416 shares

Net Sell 1 txn

Insider ten Bosch John Roderick

Role SVP of Laboratory Operations

Sold 1,416 shs ($170K)

Type	Security	Shares	Price	Value
Sale	Class A Common Stock	1,416	$120.00	$170K

Holdings After Transaction: Class A Common Stock — 33,552 shares (Direct)

Footnotes (1)

1. 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.

Key Figures

Shares sold: 1,416 shares Sale price per share: $120.00 per share Shares held after transaction: 33,552 shares +2 more

5 metrics

Shares sold 1,416 shares Class A Common Stock sold on June 29, 2026

Sale price per share $120.00 per share Open-market sale on June 29, 2026

Shares held after transaction 33,552 shares Direct ownership following reported sale

Transaction code Code S (sale) Sale in open market or private transaction

Trading plan adoption date March 6, 2026 Rule 10b5-1 trading plan adoption

Key Terms

Rule 10b5-1 trading plan, open-market sale, Form 4, Class A Common Stock

4 terms

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.

open-market sale financial

"transaction_action": "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

Form 4 regulatory

"The transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

Class A Common Stock financial

"security_title": "Class A Common Stock""

Class A common stock is a category of a company’s shares that carries a specific set of ownership rights—most commonly defined voting power and claims on dividends—set out in the company’s charter. For investors it matters because the class determines how much influence you have over corporate decisions, the share’s likely dividend and trading behavior, and how it compares in value to other share classes, like choosing a particular seat with different privileges at the company’s decision-making table.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did BillionToOne (BLLN) disclose for John Roderick ten Bosch?

BillionToOne disclosed that SVP of Laboratory Operations John Roderick ten Bosch sold 1,416 shares of Class A Common Stock at $120.00 per share on June 29, 2026 in an open-market transaction and now directly holds 33,552 shares.

Was the BillionToOne (BLLN) insider sale made under a Rule 10b5-1 trading plan?

Yes. The filing states the transactions were effected under a Rule 10b5-1 trading plan adopted by John Roderick ten Bosch on March 6, 2026. Such plans pre-schedule trades, reducing the significance of timing decisions for investors.

How many BillionToOne (BLLN) shares does the insider hold after this Form 4 sale?

After selling 1,416 shares, John Roderick ten Bosch directly holds 33,552 shares of BillionToOne Class A Common Stock. This post-transaction balance is disclosed in the Form 4 as the total shares following the reported transaction.

What role does the insider hold at BillionToOne (BLLN) in this Form 4 filing?

The reporting person, John Roderick ten Bosch, is identified as an officer of BillionToOne with the title “SVP of Laboratory Operations.” The filing also indicates he is not a director and not a ten percent owner.

What type of transaction code appears in this BillionToOne (BLLN) Form 4?

The Form 4 lists transaction code “S,” described as a sale in an open market or private transaction. It applies to 1,416 shares of Class A Common Stock sold at a price of $120.00 per share on June 29, 2026.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 07/01/2026 - 04:23 PM EDT Learn about SEC filing dates

SEC Form 4

FORM 4

UNITED 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^*

ten Bosch John Roderick

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP of Laboratory Operations

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/29/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form 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)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	06/29/2026		S(1)		1,416	D	$120	33,552	D

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

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.

Remarks:

	/s/ Thomas P. Lynch, Attorney-in-Fact	07/01/2026
	** Signature of Reporting Person	Date
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)