Personalis CFO sells 2,931 shares for tax withholding

Personalis’ CFO and COO reported an automatic sale of shares to satisfy tax withholding from RSU vesting, with a substantial direct stake remaining.

Rhea-AI Filing Summary

Personalis, Inc. (PSNL) reported that its CFO and COO, Aaron Tachibana, had 2,931 shares of common stock sold on September 18, 2026 at $16.22 per share. According to the filing, these shares were automatically sold to cover the tax withholding obligation from the settlement of vested restricted stock units, leaving him with 195,902 shares held directly.

Insider Trade Summary

Net Seller: 2,931 shares

Net Sell 1 txn

Insider Tachibana Aaron

Role CFO AND COO

Sold 2,931 shs ($48K)

Type	Security	Shares	Price	Value
Sale	Common Stock F1	2,931	$16.22	$48K

Holdings After Transaction: Common Stock — 195,902 shares (Direct)

Footnotes (1)

1. F1. Shares automatically sold to cover tax withholding obligation from settlement of vested restricted stock units.

Key Figures

Shares sold: 2,931 shares Sale price per share: $16.22 per share Shares owned after transaction: 195,902 shares

3 metrics

Shares sold 2,931 shares Common stock sold on September 18, 2026 to cover tax withholding

Sale price per share $16.22 per share Price for the 2,931 shares sold on September 18, 2026

Shares owned after transaction 195,902 shares Direct holdings of Aaron Tachibana after the reported sale

Key Terms

restricted stock units, tax withholding obligation, open market or private transaction

3 terms

restricted stock units financial

"settlement of vested restricted stock units."

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

tax withholding obligation financial

"sold to cover tax withholding obligation from settlement"

open market or private transaction financial

"Sale in open market or private transaction"

FAQ

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

What insider transaction did PSNL’s CFO and COO report?

The CFO and COO, Aaron Tachibana, reported that 2,931 shares of Personalis common stock were sold on September 18, 2026 at $16.22 per share in a transaction described as a sale in the open market or a private transaction.

Why were Aaron Tachibana’s PSNL shares sold in this Form 4?

The filing states the 2,931 shares were automatically sold to cover the tax withholding obligation arising from the settlement of vested restricted stock units, indicating the sale was linked to RSU vesting rather than a discretionary portfolio trade.

How many PSNL shares does the CFO and COO own after this transaction?

After the reported sale to cover taxes, Aaron Tachibana directly holds 195,902 shares of Personalis common stock, as disclosed in the Form 4 following the September 18, 2026 transaction.

Was the PSNL insider sale made under a Rule 10b5-1 trading plan?

The filing’s Rule 10b5-1 checkbox is not marked, and there is no footnote stating that the transaction was made pursuant to a Rule 10b5-1 trading plan.

What was the price of the PSNL shares sold by the CFO and COO?

The 2,931 shares of Personalis common stock were sold at a price of $16.22 per share on September 18, 2026, according to the Form 4.

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

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Available on EDGAR 09/22/2026 - 04:10 PM Accepted by SEC EDGAR 09/22/2026 - 04:10 PM 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).

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^*

Tachibana Aaron

(Last) (First) (Middle)

C/O PERSONALIS, INC.

6600 DUMBARTON CIRCLE

(Street)

FREMONT CALIFORNIA 94555

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Personalis, Inc. [ PSNL ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CFO AND COO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/18/2026

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
Common Stock	09/18/2026		S		2,931(1)	D	$16.22	195,902	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. Shares automatically sold to cover tax withholding obligation from settlement of vested restricted stock units.

	/s/ Aaron Tachibana	09/22/2026
	** 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)