ROBINS HARLAN S 4

4 · Adaptive Biotechnologies Corp · Filed Mar 13, 2026

AI-generated summary of this filing

Updated Mar 14, 2026

Adaptive Biotechnologies (ADPT) CSO Harlan Robins Sells 470,266 Shares

What Happened

Harlan S. Robins, Chief Scientific Officer of Adaptive Biotechnologies (ADPT), disposed of a total of 470,266 shares on 2026-03-11 in two sell transactions at $13.17 per share for combined proceeds of approximately $6,193,403. The trades consisted of 140,666 shares (≈ $1,852,571) and 329,600 shares (≈ $4,340,832).
These sales were sell-to-cover transactions tied to the vesting of equity awards (RSUs and performance share units) and are not discretionary market-timing trades.

Key Details

Transaction date: 2026-03-11; Price per share: $13.17.
Shares sold: 140,666 (RSU-related) and 329,600 (PSU-related); total sold: 470,266.
Proceeds: about $1.85M and $4.34M respectively; total ≈ $6.19M.
Footnotes: F1 = sale required to cover tax withholding on vested RSUs; F2 = sale required to cover tax withholding on vested performance share units. Both note the sales were mandated by the issuer’s sell-to-cover election and not discretionary trades by the reporting person.
Shares owned after the transaction: not specified in the material provided.
Filing: Form 4 filed 2026-03-13 for transactions on 2026-03-11—filed within the standard reporting window (timely).

Context

Sell-to-cover transactions occur when the company’s equity plan requires withholding taxes to be satisfied by selling a portion of vested shares; they generally reflect tax obligations, not a direct signal of insider sentiment.
Transaction code S = sale. These were reported as open market or private sale type transactions per the filing.

Form 4

Period: 2026-03-11

Chief Scientific Officer

Transactions

Footnotes (2)

[F1]This transaction represents the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of RSUs. This sale is mandated by Issuer's election under the equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person.
[F2]This transaction represents the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of performance share units. This sale is mandated by the Issuer's election under its equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person.

Signature

/s/ Harlan S Robins by Kyle Piskel, Attorney-in-Fact|2026-03-13

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