Mark Lappe
CIK 1366074 · Chief Executive Officer · last filed 2026-10-14
Mark Lappe is a Chief Executive Officer who has filed 35 SEC Form 4 insider transactions across 2 companies since 2022. The most recent filing shows the insider bought $849.0K of INBX on Oct 14, 2026. Across all open-market trades the lifetime net is +$2.8M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $16.1M across reported positions. 28 SEC filings were submitted jointly with Efficacy Biotech Master Fund Ltd.
"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.
Charts
Trading activity, where the exposure sits, and each trade against the stock price.
INBX price and trades
Daily close with each Form 4 filing on this company marked: green = open-market buy, red = open-market sale, purple = grants, exercises, gifts and other non-market transactions. Marker size scales with the dollar value.
Shares held
Shares owned after each reported transaction on this company (direct holdings as reported).
Open-market buying and selling
by monthDollar value of open-market purchases (code P, up) and sales (code S, down) across all companies, by filing month. Grants, exercises and gifts are excluded.
Exposure by company
latestMost recently reported shares × current price. Faded bars (*) have had no filing in 3 years, so the person may no longer hold them. Click a bar to chart that company.
Filer Profile
SUITE 100
SAN DIEGO, CA 92130
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| INBX | Chief Executive Officer | 167,449 | $96.03 | $16.08M | $2.81M | 12 | 2026-10-14 |
| Inhibrx, Inc. (INBXV) Delisted | Chief Executive Officer | 0 | — | — | $0 | 1 | 2024-05-30 |
Recent Filings
35 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2026-10-14 | INBX | Buy (P) | +10,040 | $849.0K | EDGAR |
| 2026-09-28 | INBX | Buy (P) | +10,000 | $998.8K | EDGAR |
| 2026-09-08 | INBX | Buy (P) | +25,000 | $2.65M | EDGAR |
| 2024-09-16 | INBX | Buy (P) | +40,000 | $629.1K | EDGAR |
| 2024-09-10 | INBX | Buy (P) | +44,000 | $671.1K | EDGAR |
| 2024-09-03 | INBX | Buy (P) | +40,000 | $596.8K | EDGAR |
| 2024-08-22 | INBX | Buy (P) | +40,000 | $518.3K | EDGAR |
| 2024-05-30 | Inhibrx, Inc. (INBXV) Delisted | Disp (D) | −3,045,654 | -$91.37M | EDGAR |
| 2024-05-30 | — | Grant (A) | +761,413 | $0 | |
| 2023-03-01 | INBX | Sell (S) | −120 | -$3.0K | EDGAR |
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.