Inhibrx Biosciences, Inc.
INBX- Exchange
- Nasdaq
- Industry
- Biological Products, (No Diagnostic Substances)
- SEC CIK
- 0002007919
In the last 90 days, Inhibrx Biosciences, Inc. insiders filed 7 open-market purchases and 2 sales; 162 institutions reported holding it in 13F filings for Q2 2026, worth $1.36B in total; Viking Global Investors is the only superinvestor holding it.
Open-market trades, last 90 days
Open-market purchases (P) and sales (S) by Inhibrx Biosciences, Inc. insiders, counted by Form 4 filing. Trades with a flagged price and duplicate filings are left out.
- Open-market buys
- 7 filings
- 3 insiders, $6.35M in total
- Open-market sells
- 2 filings
- 1 insider, $279.0K in total
- Insiders trading
- 4
- Net value
- +$6.07M
- Purchases minus sales
Insider roster
Directors, officers and 10% owners who have filed a Form 4 for Inhibrx Biosciences, Inc., current and former, most recent filer first. Last reported holding is the position after the last non-derivative trade in their latest filing.
| Name | Title | Last reported holding | Last filing | Filings, past year |
|---|---|---|---|---|
| Lappe Mark | Chief Executive Officer | 170,000Indirect | Oct 14, 2026 | 3 |
| Kayyem Jon Faiz | Director | 434,360Indirect | Sep 23, 2026 | 4 |
| Forsyth Douglas | Director | 227,064Indirect | Sep 18, 2026 | 2 |
| Vuori Kristiina MD | Director | 20,443 | Sep 18, 2026 | 1 |
| Manhard Kimberly | Director | 7,500Indirect | Sep 18, 2026 | 3 |
| Matly David | President | – | Apr 27, 2026 | 1 |
| Viking Global Investors LP | 10% Owner | 102,864Indirect | Oct 9, 2025 | 0 |
| Halvorsen Ole Andreas | 10% Owner | 102,864Indirect | Oct 9, 2025 | 0 |
| Ott David C. | 10% Owner | 102,864Indirect | Oct 9, 2025 | 0 |
| Viking Global Opportunities Portfolio GP LLC | 10% Owner | 102,864Indirect | Oct 9, 2025 | 0 |
| Viking Global Opportunities GP LLC | 10% Owner | 102,864Indirect | Oct 9, 2025 | 0 |
| Viking Global Opportunities Illiquid Investments Sub-Master LP | 10% Owner | 102,864Indirect | Oct 9, 2025 | 0 |
| Shabet Rose Sharon | 10% Owner | 102,864Indirect | Oct 9, 2025 | 0 |
| Viking Global Opportunities Parent GP LLC | 10% Owner | 102,864Indirect | Oct 9, 2025 | 0 |
| Deck Kelly | Chief Financial Officer | – | Apr 2, 2025 | 0 |
| Inhibrx, Inc. | 10% Owner | 1,157,926 | May 31, 2024 | 0 |
| Eckelman Brendan P. | Chief Scientific Officer | 40,000Indirect | May 30, 2024 | 0 |
Insider trades
Each row adds up one type of transaction in one Form 4 filing. Only open-market purchases (P) and sales (S) are shown by default; use the filters to see grants, option exercises and other codes.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Oct 14, 2026 (view filing)6:58 PM ET | Oct 14 | Same day | Lappe MarkChief Executive Officer | PPurchase | +10.0K | $84.56 | +$849.0K | +6.3%170.0K after | 6 lots |
| Sep 28, 2026 (view filing)5:47 PM ET | Sep 25-28 | 3 days | Lappe MarkChief Executive Officer | PPurchase | +10.0K | $99.88 | +$998.8K | +1.4%740.5K after | 4 lots |
| Sep 23, 2026 (view filing)4:59 PM ET | Sep 23 | Same day | Kayyem Jon FaizDirector | PPurchase | +5.00K | $100.00 | +$500.0K | +1.2%434.4K after | |
| Sep 17, 2026 (view filing)5:46 PM ET | Sep 16 | 1 day | Kayyem Jon FaizDirector | PPurchase | +5.00K | $100.00 | +$500.0K | +1.2%429.4K after | |
| Sep 15, 2026 (view filing)5:52 PM ET | Sep 11-15 | 4 days | Manhard KimberlyDirector | SSale | −1.50K | $109.03 | −$163.5K | −16.7%7.50K after | 3 lots |
| Sep 10, 2026 (view filing)7:06 PM ET | Sep 8-9 | 2 days | Manhard KimberlyDirector | SSale | −1.00K | $115.47 | −$115.5K | −10.0%9.00K after | 2 lots |
| Sep 8, 2026 (view filing)5:23 PM ET | Sep 8 | Same day | Kayyem Jon FaizDirector | PPurchase | +5.00K | $113.52 | +$567.6K | +1.2%424.4K after | |
| Sep 8, 2026 (view filing)4:26 PM ET | Sep 8 | Same day | Forsyth DouglasDirector | PPurchase | +2.50K | $114.65 | +$286.6K | +1.1%227.1K after | |
| Sep 8, 2026 (view filing)4:04 PM ET | Sep 8 | Same day | Lappe MarkChief Executive Officer | PPurchase | +25.0K | $105.82 | +$2.65M | +3.5%730.5K after | 6 lots |
| Oct 9, 2025 (view filing)4:41 PM ET | Oct 7 | 2 days | Viking Global Investors LP and 7 others10% Owner | SSale | −350.0K | $32.25 | −$11.3M | −77.3%102.9K after | 3 lots |
| Nov 22, 2024 (view filing) | Nov 19-20 | 3 daysLate | Kayyem Jon FaizDirector | PPurchase | +107.2K | $14.22 | +$1.52M | New position69.8K after | 4 lots |
| Oct 7, 2024 (view filing) | Oct 3 | 4 days | Vuori Kristiina MDDirector | PPurchase | +6.67K | $15.00 | +$100.0K | +48.4%20.4K after | |
| Sep 16, 2024 (view filing) | Sep 12-16 | 4 days | Lappe MarkChief Executive Officer | PPurchase | +40.0K | $15.73 | +$629.1K | +6.0%705.5K after | 2 lots |
| Sep 12, 2024 (view filing) | Sep 10-11 | 2 days | Vuori Kristiina MDDirector | PPurchase | +6.64K | $15.07 | +$100.0K | +92.9%13.8K after | 2 lots |
| Sep 10, 2024 (view filing) | Sep 6-10 | 4 days | Lappe MarkChief Executive Officer | PPurchase | +44.0K | $15.25 | +$671.1K | +7.1%665.5K after | 3 lots |
| Sep 3, 2024 (view filing) | Aug 29-Sep 3 | 5 days | Lappe MarkChief Executive Officer | PPurchase | +40.0K | $14.92 | +$596.8K | +32.0%165.0K after | 4 lots |
| Sep 3, 2024 (view filing) | Aug 29 | 5 days | Vuori Kristiina MDDirector | PPurchase | +7.14K | $14.00 | +$100.0K | New position7.14K after | |
| Aug 30, 2024 (view filing) | Aug 28 | 2 days | Manhard KimberlyDirector | PPurchase | +10.0K | $13.98 | +$139.8K | New position10.0K after | |
| Aug 26, 2024 (view filing) | Aug 22-23 | 4 days | Forsyth DouglasDirector | PPurchase | +75.0K | $13.83 | +$1.04M | +50.1%224.6K after | 2 lots |
| Aug 22, 2024 (view filing) | Aug 20-21 | 2 days | Lappe MarkChief Executive Officer | PPurchase | +40.0K | $12.96 | +$518.3K | +269.1%54.9K after | 2 lots |
| Jun 7, 2024 (view filing) | Jun 5 | 2 days | Kayyem Jon FaizDirector | PPurchase | +57.5K | $17.32 | +$997.0K | +5.3%1.15M after | 2 lots |
| Jun 4, 2024 (view filing) | May 31-Jun 4 | 4 days | Kayyem Jon FaizDirector | PPurchase | +286.8K | $17.18 | +$4.93M | +35.6%1.09M after | 5 lots |