Adaptive Biotech CCO sells 1,195 shares at $27

Adaptive Biotechnologies’ Chief Commercial Officer, MRD, sold a small block of shares under a pre-arranged Rule 10b5-1 trading plan.

Rhea-AI Filing Summary

Adaptive Biotechnologies Corp (ADPT) reported that Chief Commercial Officer, MRD, Susan Bobulsky sold 1,195 shares of common stock on September 15, 2026, at a price of $27.00 per share in an open-market or private transaction. After this sale, she held 395,794 shares directly.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by Susan Bobulsky on December 16, 2025.

Insider Trade Summary 10b5-1

Net Seller: 1,195 shares

Net Sell 1 txn

Insider BOBULSKY SUSAN

Role Chief Commercial Officer, MRD

Sold 1,195 shs ($32K)

Type	Security	Shares	Price	Value
Sale	Common Stock F1	1,195	$27.00	$32K

Holdings After Transaction: Common Stock — 395,794 shares (Direct)

Footnotes (1)

1. F1. The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 16, 2025.

Key Figures

Shares sold: 1,195 shares Sale price per share: $27.00 per share Shares held after transaction: 395,794 shares +2 more

5 metrics

Shares sold 1,195 shares Common stock sale reported for September 15, 2026

Sale price per share $27.00 per share Common stock transaction on September 15, 2026

Shares held after transaction 395,794 shares Direct holdings of Susan Bobulsky following the sale

Rule 10b5-1 plan adoption date December 16, 2025 Trading plan under which the sale was effected

Net shares sold in filing 1,195 shares Net selling activity reported for this Form 4

Key Terms

Rule 10b5-1 trading plan, open market or private transaction

2 terms

Rule 10b5-1 trading plan regulatory

"The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 16, 2025."

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 or private transaction market

"Sale in open market or private transaction"

FAQ

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

What insider transaction did ADPT disclose for Susan Bobulsky?

Adaptive Biotechnologies disclosed that Susan Bobulsky sold 1,195 shares of common stock on September 15, 2026 at $27.00 per share in an open-market or private transaction under a Rule 10b5-1 trading plan.

How many ADPT shares does Susan Bobulsky hold after this sale?

After the reported sale, Susan Bobulsky directly holds 395,794 shares of Adaptive Biotechnologies common stock, as stated in the filing.

Was the ADPT insider sale by Susan Bobulsky under a Rule 10b5-1 plan?

Yes. The filing states the transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by Susan Bobulsky on December 16, 2025.

What price did Susan Bobulsky receive per ADPT share in this transaction?

Susan Bobulsky’s reported transaction in Adaptive Biotechnologies common stock was executed at a price of $27.00 per share on September 15, 2026 in an open-market or private transaction.

What is Susan Bobulsky’s role at Adaptive Biotechnologies (ADPT)?

Susan Bobulsky is identified in the filing as Chief Commercial Officer, MRD of Adaptive Biotechnologies Corp.

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

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Available on EDGAR 09/17/2026 - 06:50 PM Accepted by SEC EDGAR 09/17/2026 - 06:50 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).

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^*

BOBULSKY SUSAN

(Last) (First) (Middle)

C/O ADAPTIVE BIOTECHNOLOGIES CORPORATION

1165 EASTLAKE AVENUE EAST

(Street)

SEATTLE WASHINGTON 98109

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Commercial Officer, MRD

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/15/2026

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	09/15/2026		S(1)		1,195	D	$27	395,794	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 in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 16, 2025.

	Susan Bobulsky by Kyle Piskel, Attorney-in-Fact	09/17/2026
	** 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)