Adaptive Biotechnologies (ADPT) director sells 15,394 shares in open market trade

Rhea-AI Filing Summary

Adaptive Biotechnologies Corp director Michelle Renee Griffin reported an open-market sale of 15,394 shares of Common Stock at a weighted-average price of $13.91 per share. The shares were sold in multiple trades between $13.84 and $13.96. After this sale, she directly holds 15,625 shares, meaning her personal stake was significantly reduced but she continues to own stock in the company.

Positive

• None.

Negative

• A company director executed an open-market sale of 15,394 shares at a weighted-average price of $13.91, materially reducing her directly held stake while still retaining 15,625 shares.

Insights

Insider trading and governance analyst

Director makes sizable open-market sale but retains a meaningful share position.

Director Michelle Renee Griffin executed an open-market sale of 15,394 shares of Adaptive Biotechnologies Corp Common Stock at a weighted-average price of $13.91. The price range for these trades was between $13.84 and $13.96, indicating execution around a tight market band.

Following the transaction, Griffin directly holds 15,625 shares. Based on the filing alone, the sale represents a substantial reduction of her directly held shares, but she retains a notable equity interest. No derivative positions are listed, so this appears as a straightforward share sale without related option exercises.

The transaction is an open-market sale, which typically carries more informational weight than purely administrative movements such as tax withholding or grants. However, the filing does not reference any Rule 10b5-1 trading plan, broader portfolio context, or company-specific catalysts, so the ultimate significance for investors depends on how this scale of selling compares with her historical activity and the company’s overall share float, which are not detailed here.

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^*

GRIFFIN MICHELLE RENEE

(Last) (First) (Middle)

C/O ADAPTIVE BIOTECHNOLOGIES CORPORATION

1165 EASTLAKE AVENUE EAST

(Street)

SEATTLE WA 98109

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Adaptive Biotechnologies Corp [ ADPT ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
03/11/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

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

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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	03/11/2026		S		15,394	D	$13.91(1)	15,625	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 price reported for this transaction is a weighted-average price. The shares were sold in multiple transactions ranging from $13.84 to $13.96, inclusive. The reporting person undertakes to provide to Adaptive Biotechnologies Corporation, any security holder of Adaptive Biotechnologies Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in any footnotes to this Form 4.

	/s/ Michelle Renee Griffin by Kyle Piskel, Attorney-in-Fact	03/13/2026
	** 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.

FAQ

What insider transaction did Adaptive Biotechnologies (ADPT) report on this Form 4?

Adaptive Biotechnologies reported that director Michelle Renee Griffin sold 15,394 shares of Common Stock in an open-market transaction. The weighted-average sale price was $13.91 per share, with trades executed within a narrow price range between $13.84 and $13.96.

At what price did the Adaptive Biotechnologies (ADPT) director sell shares?

The director’s sale was reported at a weighted-average price of $13.91 per share. According to the filing, the 15,394 shares were sold in multiple transactions, with individual trade prices ranging from $13.84 to $13.96, inclusive, during the reported trading session.

How many Adaptive Biotechnologies (ADPT) shares does Michelle Renee Griffin own after the sale?

After the reported transaction, Michelle Renee Griffin directly owns 15,625 shares of Adaptive Biotechnologies Common Stock. The Form 4 shows this balance as her total direct holdings following the 15,394-share open-market sale disclosed in the filing for the indicated transaction date.

Was the Adaptive Biotechnologies (ADPT) director sale a single trade or multiple trades?

The sale was executed as multiple trades, not a single transaction. The filing notes a weighted-average sale price and discloses that individual trades occurred within a price range of $13.84 to $13.96, with the insider offering to provide detailed breakdowns upon request.

Does the Form 4 for Adaptive Biotechnologies (ADPT) include any option exercises or derivative transactions?

No derivative or option exercises are listed in this Form 4. The filing reports only a non-derivative open-market sale of Common Stock totaling 15,394 shares, and the derivative holdings section shows no remaining derivative positions associated with the reporting person.

Is the insider sale at Adaptive Biotechnologies (ADPT) described as an open-market transaction?

Yes, the transaction is characterized as an open-market sale of Common Stock. The Form 4 uses a sale code with a description indicating a sale in the open market or a private transaction, and provides a weighted-average sale price with a specified intraday price range.