Inhibrx (INBX) Director Jon Faiz Kayyem Buys 5,000 Shares

What Happened
Jon Faiz Kayyem, a director of Inhibrx Biosciences, acquired 5,000 shares of INBX on 2026-09-16 at $100.00 per share, for a total transaction value of $500,000. The transaction is reported as a purchase (code P) — an acquisition rather than a sale.

Key Details

• Transaction date: 2026-09-16; filing date: 2026-09-17. Reported as an open‑market or private purchase (P).
• Price and quantity: 5,000 shares at $100.00 each; total value $500,000.
• Shares owned after transaction: Not specified in the public Form 4 filing.
• Footnotes: Securities are held directly by related trusts and custodial accounts (The Jon F. Kayyem and Paige Gates‑Kayyem Family Trust; Jon Faiz Kayyem Revocable Trust; Paige‑Gates Kayyem Revocable Trust) and custodial accounts for two minor children. Kayyem is trustee for some trusts and disclaims beneficial ownership of certain holdings except to the extent of any indirect pecuniary interest.
• Timeliness: Filing was submitted the day after the transaction; no late filing indicated.

Context
Purchases by directors are often watched by investors because they indicate the insider put personal capital into the company, but filings do not state motivation. These shares are held through family trusts and custodial accounts (per footnotes), which can affect how beneficial ownership is reported. This transaction is a straightforward equity purchase — not an option exercise, award, or gift.