Latest filingSep 08, 2026Most recent Form 4
INBX
Inhibrx Biosciences, Inc.
Insider activity for last month from 08/09 to 09/09. Counts use processed Form 4 rows. Purchase and sale metrics use codes P and S; totals remain unknown when any matching value is missing. Rows without a usable transaction date cannot be assigned to a rolling period and are excluded.
Total buying$349M8 buys
Total selling$00 sells
Net open-market+$349M3 insiders
Open-market mix
Buy vs sell distribution by transaction countInsider activity report
Monthly open-market purchase and sale counts Buys Sells
Transaction codes
By Form 4 transaction code in selected period8transactions
- P · Open-market buys · dominant8 · 100%
Activity by reported role
A joint filing can contribute to multiple roles8transactions
- Chief executive officer · dominant6 · 75%
- Director2 · 25%
Distinct insiders active
Reporting-owner CIKs by month · peak Sep 2026 (3)Aug 2026Sep 2026
Reported Holdings After
Separated by insider, security, and ownership typeLappe MarkCommon Stock · Indirect · By the Lappe Family Trust
720,867Sep 08, 2026
Forsyth DouglasCommon Stock · Indirect · By the Forsyth Family Trust Dated July 20, 2001
227,064Sep 08, 2026
Kayyem Jon FaizCommon Stock · Indirect · By The Jon F. Kayyem and Paige Gates-Kayyem Family Trust
424,360Sep 08, 2026
These are reported post-transaction holdings, not company-wide ownership percentages. Securities, indirect vehicles, and amendments are kept separate.
Filing activity heatmap
Each cell is one day · intensity = transactions · buys green, sells redAug 09 → Sep 09
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Top insiders
By absolute net value across the selected period- LM+$2.6M
- KF+$567.6k
- FD+$286.6k
Filing detail checks
Secondary metrics for the selected periodFiling-only signals
Deterministic matches in the selected period
No filing-only signal badges matched this period.
INBX transaction history
Filters apply within this company and selected period by default| Ticker | Insider | Role | Type | Shares | Value | Code | Signals | 90d return | Filed | Trans date |
|---|---|---|---|---|---|---|---|---|---|---|
| INBX | Kayyem Jon Faiz | DIR | buy | 5.00k | $56.7M | P | — | 0.0% | 09/08 | 09/08 |
| INBX | FORSYTH DOUGLAS | DIR | buy | 2.50k | $28.6M | P | — | 0.0% | 09/08 | 09/08 |
| INBX | Lappe Mark | CEO | buy | 9.68k | $108M | P | — | — | 09/08 | 09/08 |
| INBX | Lappe Mark | CEO | buy | 1.21k | $13.6M | P | — | — | 09/08 | 09/08 |
| INBX | Lappe Mark | CEO | buy | 500 | $5.41M | P | — | — | 09/08 | 09/08 |
| INBX | Lappe Mark | CEO | buy | 1.10k | $11.7M | P | — | — | 09/08 | 09/08 |
| INBX | Lappe Mark | CEO | buy | 6.60k | $66.4M | P | — | — | 09/08 | 09/08 |
| INBX | Lappe Mark | CEO | buy | 5.89k | $58.5M | P | — | — | 09/08 | 09/08 |
Inhibrx Biosciences, Inc. Insider Activity FAQ
SEC Form 4 contextWho recently reported transactions at Inhibrx Biosciences, Inc.?
Kayyem Jon Faiz, FORSYTH DOUGLAS, Lappe Mark.
When was the latest reported open-market purchase?
Kayyem Jon Faiz reported a buy on Sep 08, 2026 valued at $56.7M. Read the SEC filing.
When was the latest reported open-market sale?
No code-S sale is available for this period.
What is the recent purchase and sale balance?
Net open-market buying in the selected period was $3,499,596.56. This describes filed transactions, not a bullish rating.
Where can I see the original SEC filing?
Every transaction row and latest-activity fact links to its original SEC filing.
What do these Form 4 transaction codes mean?
P and S generally describe open-market or private purchases and sales. A, D, F, M, X, G, J, and V describe awards, issuer dispositions, tax withholding, exercises, gifts, other transactions, and voluntary early reports; review each filing and its footnotes for context.