Form 4: Arcellx Director & Officer Elghandour Reports Share Acquisitions

Arcellx, Inc. Director and Officer Rami Elghandour reported the acquisition of 164,548 common shares through the vesting and conversion of restricted stock units, alongside a new RSU grant.

Summary

• Rami Elghandour, a Director and Officer of Arcellx, Inc., reported transactions involving the company's common stock and restricted stock units (RSUs) under a Rule 10b5-1(c) plan.
• On January 2, 2026, Elghandour acquired 55,459 shares of common stock at a price of $0, increasing his direct beneficial ownership to 673,378 shares. This acquisition resulted from the conversion of RSUs.
• On January 3, 2026, an additional 53,098 shares of common stock were acquired at $0, bringing his direct beneficial ownership to 726,476 shares, also from RSU conversion.
• On January 6, 2026, 55,991 shares of common stock were acquired at $0, resulting in a total direct beneficial ownership of 782,467 shares, again from RSU conversion.
• A new grant of 208,333 restricted stock units was received on January 2, 2026, which will vest 1/4th annually over four years, contingent on continued service.
• Several tranches of previously granted RSUs vested and converted into common stock: 55,459 RSUs from a January 2, 2024 grant, 53,098 RSUs from a January 3, 2023 grant, and 55,991 RSUs from a January 6, 2025 grant.
• Following these transactions, Elghandour holds 782,467 shares of common stock directly and has remaining derivative holdings of 208,333 RSUs (from the new grant), 55,459 RSUs (from the January 2, 2024 grant), and 167,973 RSUs (from the January 6, 2025 grant).

Sentiment

Score: 6

Explanation: The filing reports routine insider transactions related to executive compensation, specifically the vesting of restricted stock units and a new RSU grant. While not indicative of new strategic developments, the increase in direct common stock ownership by a key executive is generally viewed as a positive alignment of interests.

Positives

• An insider (Rami Elghandour) is increasing his direct beneficial ownership of common stock, which generally aligns his interests with those of other shareholders.
• The acquisition of shares through RSU vesting demonstrates continued commitment to the company by a key executive.
• A new grant of 208,333 RSUs indicates ongoing long-term incentive compensation for the reporting person, encouraging retention and performance.

Risks

• The vesting of restricted stock units is contingent upon the reporting person continuing to be a 'Service Provider' to Arcellx, Inc., meaning future share acquisitions are not guaranteed if employment ceases.

Future Outlook

NA

Industry Context

NA

Related Party Transactions

• The restricted stock unit grants and subsequent vesting represent compensation arrangements between Arcellx, Inc. and its Director and Officer, Rami Elghandour.

Stakeholder Impact

• Shareholders: Increased alignment of interests with a key executive due to higher direct common stock ownership. Potential minor dilution from the issuance of new shares upon RSU vesting.
• Employees (specifically Rami Elghandour): Continued long-term incentive compensation through RSU grants, contingent on continued service.

Next Steps

• Future vesting of 208,333 RSUs granted on January 2, 2026, with 1/4th vesting annually over four years, contingent on continued service.
• Future vesting of the remaining 55,459 RSUs from the January 2, 2024 grant, which vest 1/3rd annually over three years, contingent on continued service.
• Future vesting of the remaining 167,973 RSUs from the January 6, 2025 grant, which vest 1/4th annually over four years, contingent on continued service.

Key Dates

Keywords

Arcellx, ACLX, insider transaction, restricted stock units, RSU, common stock, beneficial ownership, executive compensation, director, officer