Briggs Morrison
CIK 1654430 · President, Head of R&D · last filed 2026-06-26
"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.
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Disclosed Exposure
$1.58M
Companies
8
Total Filings
64
Lifetime Open-Market Net
-$27.68M
Filer Profile
Reported Address
C/O SYNDAX PHARMACEUTICALS, INC.400 TOTTEN POND ROAD, SUITE 110
WALTHAM, MA 02451
Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses.
View filings on SEC EDGAR.
Holdings By Company
Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| ARVN | Director | 111,548 | $8.45 | $942.6K | -$2.18M | 14 | 2026-06-26 |
| CRSP | Director | — | $51.72 | — | $0 | 2 | 2026-06-09 |
| HOWL | Director | — | $0.98 | — | $0 | 5 | 2025-06-13 |
| Carisma Therapeutics Inc. (CARM) Delisted | Director | — | $0.00 | — | $0 | 2 | 2024-06-27 |
| Repare Therapeutics Inc. (RPTX) Delisted | Director | 4,800 | $2.65 | $12.7K | $96.0K | 5 | 2024-06-20 |
| SNDX | Director | 34,836 | $18.18 | $633.3K | -$25.70M | 27 | 2024-02-09 |
| Codiak BioSciences, Inc. (CDAK) Delisted | Director | 4,761 | $0.06 | $271 | $100.0K | 2 | 2021-02-17 |
| NXTC | Director | — | $7.00 | — | $0 | 2 | 2020-06-15 |
Recent Filings · Page 4 of 7
64 filingsInsider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2022-09-16 | SNDX | Mixed | — | -$4.40M | EDGAR |
| 2022-07-05 | SNDX | Mixed | — | -$734.9K | EDGAR |
| 2022-06-21 | ARVN | Grant (A) | — | $0 | EDGAR |
| 2022-06-03 | HOWL | Grant (A) | — | $0 | EDGAR |
| 2022-05-16 | Repare Therapeutics Inc. (RPTX) Delisted | Grant (A) | — | $0 | EDGAR |
| 2022-04-18 | ARVN | Mixed | −4,772 | -$1.13M | EDGAR |
| 2022-04-13 | SNDX | Exer (M) | +73,673 | $530.4K | EDGAR |
| 2022-04-05 | SNDX | Mixed | −30,500 | -$1.02M | EDGAR |
| 2022-02-03 | SNDX | Grant (A) | — | $0 | EDGAR |
| 2022-01-19 | ARVN | Mixed | −4,772 | -$1.12M | EDGAR |
Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
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.
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.