Gilson Michelle 4

What Happened
Michelle Gilson, Chief Financial Officer of Arcellx, converted 20,496 restricted stock units (RSUs) into 20,496 shares on Jan 2, 2026 (conversion/exercise of a derivative at $0). On Feb 17, 2026 she sold a total of 11,291 shares: 7,141 shares sold at a weighted average price of $69.21 (proceeds ~$494,231) and 4,150 shares sold at a weighted average price of $70.01 (proceeds ~$290,552). Combined proceeds from the Feb 17 sales were approximately $784,783. The filings indicate one of the sales was a broker-assisted sale to satisfy tax withholding related to RSU vesting.

Key Details

• Transaction dates: Jan 2, 2026 (RSU conversion); Feb 17, 2026 (sales). Form 4 filed Feb 18, 2026 (timely).
• Sale details: 7,141 shares at weighted avg $69.21 (range $68.69–$69.68); 4,150 shares at weighted avg $70.01 (range $69.69–$70.55). Full per-share breakdown available on request per the filing.
• Proceeds: ~ $494,231 and ~$290,552, total ~$784,783.
• Shares owned after transaction: not specified in the provided filing details.
• Footnotes: F1 notes these were RSUs (1 RSU = 1 share) with vesting previously reported; F2 confirms a broker-assisted sale to satisfy tax withholding; F3/F4 explain weighted-average prices and availability of exact per-price sale counts on request.
• Nature of trades: conversion of RSUs (no cash paid) followed by broker-assisted and open-market sales (routine tax-withholding and disposition).

Context
The Jan 2 conversion reflects RSU vesting (a non‑cash issuance of shares). The broker-assisted sale to cover tax withholding is a common, routine action following RSU vesting and does not necessarily indicate a change in insider sentiment. Sales by executives can be routine for tax or diversification reasons; purchases are generally more indicative of bullish insider conviction.