INBX
Inhibrx Biosciences, Inc.
Inhibrx Biosciences, Inc. insider trading
Insiders at Inhibrx Biosciences, Inc. have been buying its stock on the open market. The largest purchase in the last 30 days was Lappe Mark (Chief Executive Officer · Director) buying $1.1M of INBX, filed Sep 08, 2026. Every open-market purchase and sale its officers, directors and 10% owners filed in that time is listed below, each linked to the original Form 4.
- Bought on the open market
- $3.5M
- Sold
- —
- Insiders
- 3
- Latest trade
- Sep 08, 2026
From SEC filings · last 30 days
Recent INBX insider transactions
Lappe MarkChief Executive Officer · Director
Bought 9,681 sh at $112.28 · Sep 08, 2026
$1.1M
FilingLappe MarkChief Executive Officer · Director
Bought 6,605 sh at $100.64 · Sep 08, 2026
$664.7K
FilingLappe MarkChief Executive Officer · Director
Bought 5,895 sh at $99.29 · Sep 08, 2026
$585.3K
FilingKayyem Jon FaizDirector
Bought 5,000 sh at $113.52 · Sep 08, 2026
$567.6K
FilingForsyth DouglasDirector
Bought 2,500 sh at $114.65 · Sep 08, 2026
$286.6K
FilingLappe MarkChief Executive Officer · Director
Bought 1,219 sh at $111.88 · Sep 08, 2026
$136.4K
FilingLappe MarkChief Executive Officer · Director
Bought 1,100 sh at $107.12 · Sep 08, 2026
$117.8K
FilingLappe MarkChief Executive Officer · Director
Bought 500 sh at $108.23 · Sep 08, 2026
$54.1K
Filing
SEC Form 4 data, Q3 2024 to Q2 2026
INBX insider trading by quarter
Between Jul 01, 2024 and Jun 30, 2026, 6 insiders traded INBX on the open market: 20 purchases worth $4.7M and 3 sales worth $11.3M. In the last four quarters alone: 0 purchases and 3 sales ($11.3M), by one insider.
| Quarter | Bought | Sold | Insiders |
|---|---|---|---|
| Q2 2026 | — | — | |
| Q1 2026 | — | — | |
| Q4 2025 | — | −$11.3M3 sales | |
| Q3 2025 | — | — | |
| Q2 2025 | — | — | |
| Q1 2025 | — | — | |
| Q4 2024 | +$861.9K3 buys | — | |
| Q3 2024 | +$3.8M17 buys | — |
- Largest purchase
- +$841.6K of INBX by Forsyth Douglas (Director) on Aug 23, 2024.
- Largest sale
- −$10M of INBX by Viking Global Opportunities Parent GP LLC (10% Owner) on Oct 07, 2025.
Open-market transactions through Jun 30, 2026most recent first
Viking Global Opportunities Parent GP LLC
10% Owner
−$10M
Oct 07, 2025
308,643 sh · $32.25
Viking Global Opportunities Parent GP LLC
10% Owner
−$807.6K
Oct 07, 2025
25,042 sh · $32.25
Viking Global Opportunities Parent GP LLC
10% Owner
−$526.2K
Oct 07, 2025
16,315 sh · $32.25
Kayyem Jon Faiz
Director
+$266.1K
Nov 20, 2024
18,750 sh · $14.19
Kayyem Jon Faiz
Director
+$495.8K
Nov 19, 2024
34,843 sh · $14.23
Vuori Kristiina MD
Director
+$100K
Oct 03, 2024
6,667 sh · $15.00
Lappe Mark
Chief Executive Officer · Director
+$223.3K
Sep 16, 2024
13,037 sh · $17.13
Lappe Mark
Chief Executive Officer · Director
+$405.8K
Sep 12, 2024
26,963 sh · $15.05
Vuori Kristiina MD
Director
+$97.3K
Sep 11, 2024
6,457 sh · $15.07
Lappe Mark
Chief Executive Officer · Director
+$129.1K
Sep 10, 2024
8,500 sh · $15.19
Vuori Kristiina MD
Director
+$2.7K
Sep 10, 2024
179 sh · $15.00
Lappe Mark
Chief Executive Officer · Director
+$144.5K
Sep 09, 2024
9,500 sh · $15.21
Lappe Mark
Chief Executive Officer · Director
+$397.5K
Sep 06, 2024
26,000 sh · $15.29
Lappe Mark
Chief Executive Officer · Director
+$239.4K
Sep 03, 2024
15,288 sh · $15.66
Lappe Mark
Chief Executive Officer · Director
+$76.9K
Sep 03, 2024
4,712 sh · $16.31
| Date | Insider | Shares | Price | Value |
|---|---|---|---|---|
| Oct 07, 2025 | Viking Global Opportunities Parent GP LLC10% Owner | 308,643 | $32.25 | −$10M |
| Oct 07, 2025 | Viking Global Opportunities Parent GP LLC10% Owner | 25,042 | $32.25 | −$807.6K |
| Oct 07, 2025 | Viking Global Opportunities Parent GP LLC10% Owner | 16,315 | $32.25 | −$526.2K |
| Nov 20, 2024 | Kayyem Jon FaizDirector | 18,750 | $14.19 | +$266.1K |
| Nov 19, 2024 | Kayyem Jon FaizDirector | 34,843 | $14.23 | +$495.8K |
| Oct 03, 2024 | Vuori Kristiina MDDirector | 6,667 | $15.00 | +$100K |
| Sep 16, 2024 | Lappe MarkChief Executive Officer · Director | 13,037 | $17.13 | +$223.3K |
| Sep 12, 2024 | Lappe MarkChief Executive Officer · Director | 26,963 | $15.05 | +$405.8K |
| Sep 11, 2024 | Vuori Kristiina MDDirector | 6,457 | $15.07 | +$97.3K |
| Sep 10, 2024 | Lappe MarkChief Executive Officer · Director | 8,500 | $15.19 | +$129.1K |
| Sep 10, 2024 | Vuori Kristiina MDDirector | 179 | $15.00 | +$2.7K |
| Sep 09, 2024 | Lappe MarkChief Executive Officer · Director | 9,500 | $15.21 | +$144.5K |
| Sep 06, 2024 | Lappe MarkChief Executive Officer · Director | 26,000 | $15.29 | +$397.5K |
| Sep 03, 2024 | Lappe MarkChief Executive Officer · Director | 15,288 | $15.66 | +$239.4K |
| Sep 03, 2024 | Lappe MarkChief Executive Officer · Director | 4,712 | $16.31 | +$76.9K |
From SEC's quarterly Form 3, 4 and 5 data sets: code P purchases and code S sales of common stock, by the date the trade happened. Where a fund and the people who control it each report the same block, it is counted once. Trades made in the last days of Q2 2026 but filed after it closed arrive with SEC's next quarterly release.
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Questions
- Are INBX insiders buying or selling?
- Between Sep 08, 2026 and Sep 08, 2026, 3 Inhibrx Biosciences, Inc. insiders made 8 open-market purchases worth $3.5M and no sales, a net purchase of $3.5M.
- How much INBX stock have insiders bought and sold in the last two years?
- Between Jul 01, 2024 and Jun 30, 2026, 6 Inhibrx Biosciences, Inc. insiders made 20 open-market purchases worth $4.7M and 3 sales worth $11.3M. In the four quarters to Jun 30, 2026: no purchases and 3 sales ($11.3M). The largest purchase was Forsyth Douglas buying $841.6K on Aug 23, 2024. The largest sale was Viking Global Opportunities Parent GP LLC selling $10M on Oct 07, 2025.
- What was the largest recent INBX insider trade?
- Lappe Mark (Chief Executive Officer · Director) bought $1.1M of INBX stock on Sep 08, 2026 at about $112.28 a share.
- When did an insider last buy INBX shares?
- The most recent open-market purchase on file is Lappe Mark (Chief Executive Officer · Director) buying $1.1M on Sep 08, 2026.
- Where does INBX insider trading data come from?
- From the Form 4 filings Inhibrx Biosciences, Inc.'s officers, directors and 10% owners must send the SEC within two business days of a trade. Each row on this page links to its original filing on SEC EDGAR. Share grants and option exercises are kept apart from open-market purchases and sales, because only the latter cost the insider their own money.
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