Adaptive Biotech ex-officer plans $6.4M stock sale

Adaptive Biotechnologies Corp (ADPT) received a notice that former officer Harlan Robins intends to sell shares of its common stock under Rule 144.

Rhea-AI Filing Summary

Adaptive Biotechnologies Corp (ADPT) received a notice that former officer Harlan Robins intends to sell shares of its common stock under Rule 144. The planned sale covers 261,044 shares, with an indicated aggregate market value of $6,411,240.64. Shares outstanding were listed as 159,595,842 as of 08/18/2026; this is a baseline figure, not the amount being sold.

The shares to be sold were originally acquired on 02/07/2019 as stock option compensation, with the planned transaction described as a cashless exercise / same-day sale through Goldman Sachs & Co. LLC. The notice also lists multiple prior common stock sales by Harlan Robins in the preceding three months, including blocks of 250,000 shares on 07/02/2026 and 207,600 shares plus 284,800 shares on 07/21/2026.

Key Figures

Shares to be sold: 261,044 shares Aggregate market value of planned sale: $6,411,240.64 Shares outstanding: 159,595,842 shares +3 more

6 metrics

Shares to be sold 261,044 shares Planned Rule 144 sale of Adaptive Biotechnologies common stock

Aggregate market value of planned sale $6,411,240.64 Value associated with 261,044 shares to be sold

Shares outstanding 159,595,842 shares Common stock outstanding as of 08/18/2026

Past sale on 07/02/2026 250,000 shares One of several sales by Harlan Robins listed in the prior three months

Past sale on 07/21/2026 284,800 shares Common stock sale by Harlan Robins during the past three months

Past sale on 06/15/2026 100,000 shares Earlier common stock sale referenced in the three-month history

Key Terms

Rule 144, cashless exercise, same-day sale, stock options

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

cashless exercise financial

"Compensation -- Cashless exercise / same-day sale"

A cashless exercise is a way for an option holder to convert stock options into actual shares without paying the purchase price in cash; instead they immediately give up a portion of the newly issued shares to cover the cost and any withholding taxes. Investors care because this process increases the number of shares available and can slightly dilute existing holdings, while also signaling how insiders or employees are realizing compensation without needing cash — similar to paying for a purchase by handing over part of what you just bought.

same-day sale financial

"Compensation -- Cashless exercise / same-day sale"

stock options financial

"Acquired as compensation -- Stock Options"

Stock options are agreements that give a person the right to buy or sell a company's stock at a specific price within a certain time frame. They are often used as a reward or incentive, similar to a coupon that can be used later if the stock price rises, allowing the holder to make a profit.

FAQ

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

What does the Form 144 filing for ADPT disclose about Harlan Robins’ planned sale?

The filing states that former officer Harlan Robins plans to sell 261,044 shares of Adaptive Biotechnologies common stock under Rule 144. The shares were acquired as stock option compensation and will be sold via Goldman Sachs & Co. LLC using a cashless exercise / same-day sale.

How many Adaptive Biotechnologies (ADPT) shares are outstanding in this Form 144 notice?

The notice lists 159,595,842 shares outstanding of Adaptive Biotechnologies common stock as of 08/18/2026. This figure provides context for the company’s equity base and is separate from the 261,044 shares covered by the planned Rule 144 sale.

What were the recent ADPT stock sales by Harlan Robins mentioned in the Form 144?

The filing lists several sales, including 250,000 shares on 07/02/2026, 207,600 shares and 284,800 shares on 07/21/2026, and additional blocks such as 100,000 shares on 06/15/2026. Each entry includes sale dates, share counts, and total dollar amounts.

How was the ADPT stock originally acquired for the shares covered by this Form 144?

The shares covered by the planned sale were acquired on 02/07/2019 as stock option compensation from Adaptive Biotechnologies. The planned disposition is described as a compensation -- cashless exercise / same-day sale, meaning the options are exercised and sold in one transaction.

Who is acting as broker for the planned ADPT share sale under this Form 144?

The notice identifies Goldman Sachs & Co. LLC, located at 200 West Street, New York, NY, as the broker handling the transaction. Goldman Sachs will facilitate the cashless exercise / same-day sale of the 261,044 shares on behalf of Harlan Robins.

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

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 08/18/2026 - 05:45 PM Accepted by SEC EDGAR 08/18/2026 - 05:45 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001780851
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Adaptive Biotechnologies Corporation
SEC File Number	001-38957
Address of Issuer	1165 Eastlake Avenue East Seattle WASHINGTON 98109
Phone	1-206-659-0067
Name of Person for Whose Account the Securities are To Be Sold	Harlan Robins
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Former Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common Stock	Goldman Sachs & Co. LLC 200 West Street New York NY 10282	261044	6411240.64	159595842	08/18/2026	NASD

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common Stock	02/07/2019	Acquired as compensation -- Stock Options	The Issuer			261044	02/07/2019	Compensation -- Cashless exercise / same-day sale

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Harlan Robins 1165 Eastlake Avenue East Seattle WA 98109	Common Stock	08/17/2026	152036	3765931.72
Harlan Robins 1165 Eastlake Avenue East Seattle WA 98109	Common Stock	08/17/2026	148956	3689640.12
Harlan Robins 1165 Eastlake Avenue East Seattle WA 98109	Common Stock	06/15/2026	100000	1737460
Harlan Robins 1165 Eastlake Avenue East Seattle WA 98109	Common Stock	06/16/2026	6160	110945.91
Harlan Robins 1165 Eastlake Avenue East Seattle WA 98109	Common Stock	07/02/2026	136240	2936094.62
Harlan Robins 1165 Eastlake Avenue East Seattle WA 98109	Common Stock	07/02/2026	250000	5565550
Harlan Robins 1165 Eastlake Avenue East Seattle WA 98109	Common Stock	07/21/2026	207600	4538136
Harlan Robins 1165 Eastlake Avenue East Seattle WA 98109	Common Stock	07/21/2026	284800	6225728

144: Remarks and Signature

Remarks
Date of Notice	08/18/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	Goldman Sachs & Co. LLC on behalf of Harlan Robins
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)