ROBINS HARLAN S 4

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.