Inhibrx Biosciences, Inc.
Ownership
Ownership Structure
Who owns Inhibrx Biosciences, Inc. (INBX)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 58.5% of the shares are freely tradable; institutional investors hold 83.1%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Viking Global Investors LP | 9.77 | 1,437,705 | +0.0 | 03/31/2026 |
| Perceptive Advisors LLC | 8.82 | 1,297,763 | -10.0 | 06/30/2026 |
| Morgan Stanley - Brokerage Accounts | 8.58 | 1,263,078 | +8.2 | 03/31/2026 |
| Sanofi | 7.87 | 1,157,926 | +0.0 | 06/30/2026 |
| HighTower Advisors, LLC | 5.91 | 870,200 | +0.0 | 03/31/2026 |
| BlackRock Inc | 5.43 | 798,898 | +2.8 | 03/31/2026 |
| State Street Corp | 3.74 | 550,845 | +46.9 | 03/31/2026 |
| Vanguard Capital Management, LLC | 3.31 | 486,422 | +0.0 | 03/31/2026 |
| Sofinnova Ventures | 2.76 | 406,029 | -10.7 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| State Street® SPDR® S&P® Biotech ETF | 2.88 | 423,246 | -1.1 | 08/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Lappe Mark | Chief Executive Officer | 730,548 | 76,488,376 $ | Sep 8, 2026 | indirect |
| Kayyem Jon Faiz | Director | 424,360 | 44,430,492 $ | Sep 8, 2026 | indirect |
| Forsyth Douglas | Director | 227,064 | 23,773,601 $ | Sep 8, 2026 | indirect |
| Manhard Kimberly | Director | 7,500 | 785,250 $ | Sep 15, 2026 | indirect |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Sep 15, 2026 | Manhard Kimberly | Director | Sell | 500 | 105.05 | 52,525 |
| Sep 14, 2026 | Manhard Kimberly | Director | Sell | 500 | 110.26 | 55,130 |
| Sep 11, 2026 | Manhard Kimberly | Director | Sell | 500 | 111.78 | 55,888 |
| Sep 9, 2026 | Manhard Kimberly | Director | Sell | 500 | 115.80 | 57,898 |
| Sep 8, 2026 | Manhard Kimberly | Director | Sell | 500 | 115.14 | 57,570 |
| Sep 8, 2026 | Kayyem Jon Faiz | Director | Buy | 5,000 | 113.52 | 567,580 |
| Sep 8, 2026 | Lappe Mark | Chief Executive Officer | Buy | 9,681 | 112.28 | 1,087,001 |
| Sep 8, 2026 | Lappe Mark | Chief Executive Officer | Buy | 1,219 | 111.88 | 136,382 |
| Sep 8, 2026 | Lappe Mark | Chief Executive Officer | Buy | 500 | 108.24 | 54,118 |
| Sep 8, 2026 | Lappe Mark | Chief Executive Officer | Buy | 1,100 | 107.12 | 117,836 |
| Sep 8, 2026 | Lappe Mark | Chief Executive Officer | Buy | 6,605 | 100.64 | 664,719 |
| Sep 8, 2026 | Lappe Mark | Chief Executive Officer | Buy | 5,895 | 99.29 | 585,343 |
| Sep 8, 2026 | Forsyth Douglas | Director | Buy | 2,500 | 114.65 | 286,617 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.