Gilson Michelle 4

What Happened

• Michelle Gilson, Chief Financial Officer of Arcellx (ACLX), exercised stock options (transaction code M) to acquire a total of 38,110 shares: 36,000 on April 15, 2026 and 2,110 on April 16, 2026, at an exercise price of $8.66 per share. She paid roughly $330,033 in total (36,000 × $8.66 = $311,760; 2,110 × $8.66 ≈ $18,273). The filing also shows corresponding derivative‑instrument dispositions at $0, which reflect conversion/extinguishment of the option awards into common stock. This is an acquisition (exercise of options), not a sale.

Key Details

• Dates and prices: Apr 15, 2026 — 36,000 shares @ $8.66; Apr 16, 2026 — 2,110 shares @ $8.66.
• Cash paid: about $330,033 total.
• Transaction code: M = exercise/conversion of derivative (stock option).
• Shares owned after transaction: not specified in the provided excerpt of the filing.
• Footnotes:
  • F1: Some shares are held by a family charitable foundation of which Ms. Gilson is President and over which she has voting and investment power.
  • F2: Shares were issued under the Issuer’s 2022 Equity Incentive Plan; vesting schedule began May 23, 2022 (25% after one year, then 1/48th monthly).
• Filing timeliness: Form 4 was filed Apr 17, 2026 for transactions on Apr 15–16, 2026 — appears to be timely (not marked late).

Context

• This was an exercise of vested options (not a cashless sale): Ms. Gilson paid the strike price to acquire the shares outright rather than immediately selling them. Exercises often reflect routine option vesting and compensation mechanics; they are informative as purchases but do not, by themselves, reveal the insider’s market view.
• The family foundation disclosure (F1) indicates Ms. Gilson has control over certain shares held in that vehicle; it does not necessarily mean shares were transferred to the foundation in these transactions.