Inhibrx (INBX) CEO Mark Lappe Buys 25,000 Shares

What Happened
Mark P. Lappe, Chief Executive Officer of Inhibrx Biosciences, acquired a total of 25,000 shares on September 8, 2026 via multiple open-market/private purchases (transaction code P). The purchases were reported in six lots: 5,895 @ $99.29 ($585,343); 6,605 @ $100.64 ($664,719); 1,100 @ $107.12 ($117,836); 500 @ $108.23 ($54,118); 1,219 @ $111.88 ($136,382); and 9,681 @ $112.28 ($1,087,001). Aggregate consideration for these transactions was roughly $2,645,399. These were purchases (a buy signal rather than a sale).

Key Details

• Transaction date: September 8, 2026 (all trades reported on that date).
• Transaction type/code: Open market/private purchases (P = Purchase).
• Aggregate shares bought: 25,000; aggregate reported value: ~$2.65M ($2,645,399).
• Per-lot prices shown are weighted-average prices; footnotes indicate each lot was executed in multiple trades at price ranges (reported as weighted averages).
• Ownership after transaction: Not specified in the provided excerpt of the Form 4.
• Notable footnotes: Some securities are directly owned by the Lappe Family Trust or a trust for immediate family beneficiaries; Mark P. Lappe is a trustee/related party and may be deemed to indirectly beneficially own those holdings. Other footnotes disclose that reported prices reflect weighted averages across multiple transactions and give the underlying price ranges.
• Filing timeliness: Report shows period of report and filing date of Sept 8, 2026 (same day), indicating a timely Form 4 filing in this excerpt.

Context
Insider purchases can be of interest to investors because executives are buying company stock, but they do not by themselves predict future performance. The filing shows multiple small trades aggregated and reported as weighted-average prices; trust ownership notes mean some of the shares are held indirectly by family trusts. This Form 4 reports outright purchases (not option exercises, gifts, or awards).