Personalis (PSNL) CFO & COO Aaron Tachibana Sells 2,931 Shares

What Happened
Aaron Tachibana, Personalis' Chief Financial Officer and Chief Operating Officer, sold 2,931 shares of Personalis common stock on 2026-09-18 at $16.22 per share, generating proceeds of approximately $47,541. The sale was reported as a disposition (S) and, per the filing footnote, the shares were automatically sold to cover tax withholding on vested restricted stock units (RSUs) — a routine, non‑investment sale.

Key Details

• Transaction date: 2026-09-18; filing date: 2026-09-22 (timely filed within SEC Form 4 deadlines).
• Shares sold: 2,931 at $16.22 per share; total proceeds ≈ $47,541.
• Primary reason noted: automatic sale to cover tax withholding from RSU settlement (Footnote F1).
• Transaction code: S (Sale); withholding code: F (tax withholding).
• Shares owned after transaction: not specified in the information provided here.
• Accession number for the filing: 0001401786-26-000009.

Context
Tax-withholding sales upon RSU vesting are common and typically routine administrative transactions that do not necessarily indicate the insider’s view of the company’s prospects. Purchases (in contrast) can be interpreted as stronger signals of insider confidence; this disposition appears driven by payroll/tax obligations rather than a discretionary sale.