Bruce Booth
CIK 1451612 · last filed 2026-04-24
"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
$143.47M
Companies
8
Total Filings
77
Lifetime Open-Market Net
-$112.33M
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 |
|---|---|---|---|---|---|---|---|
| KYMR | Director | 680,844 | $86.20 | $58.69M | -$127.69M | 21 | 2026-04-24 |
| SION | Director | 2,360,156 | $35.92 | $84.78M | -$21.01M | 7 | 2025-10-21 |
| Vigil Neuroscience, Inc. (VIGL) Delisted | Director | 0 | $8.05 | $0 | $7.49M | 11 | 2025-08-05 |
| Tectonic Therapeutic, Inc. (AVRO) Delisted | Director | 5,567,289 | $16.80 | $93.53M | $15.00M | 7 | 2023-06-08 |
| Dianthus Therapeutics, Inc. /DE/ (MGTA) Delisted | Director | 4,117,125 | $11.19 | $46.09M | $9.75M | 7 | 2022-06-30 |
| Cogent Biosciences, Inc. (UMRX) Delisted | Director | 3,184,446 | — | — | $1.13M | 12 | 2020-07-06 |
| Viridian Therapeutics, Inc.\DE (MGEN) Delisted | Director | 3,142,580 | — | — | $3.00M | 5 | 2018-06-28 |
| Larimar Therapeutics, Inc. (ZFGN) Delisted | Director | 4,638,028 | — | — | $0 | 7 | 2018-01-05 |
Recent Filings · Page 5 of 8
77 filingsForm 4 transactions across all companies, newest first.
| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2021-06-03 | Dianthus Therapeutics, Inc. /DE/ (MGTA) Delisted | Grant (A) | — | $0 | EDGAR |
| 2021-03-16 | KYMR | Sell (S) | −229,350 | -$12.96M | EDGAR |
| 2020-08-25 | KYMR | Conv (C) | +8,309,270 | $0 | EDGAR |
| 2020-08-21 | KYMR | Grant (A) | — | $0 | EDGAR |
| 2020-07-06 | Cogent Biosciences, Inc. (UMRX) Delisted | Grant (A) | — | $0 | EDGAR |
| 2020-07-01 | Dianthus Therapeutics, Inc. /DE/ (MGTA) Delisted | Buy (P) | +1,250,000 | $10.00M | EDGAR |
| 2020-06-11 | Cogent Biosciences, Inc. (UMRX) Delisted | Grant (A) | — | $0 | EDGAR |
| 2020-06-09 | Dianthus Therapeutics, Inc. /DE/ (MGTA) Delisted | Grant (A) | — | $0 | EDGAR |
| 2020-06-05 | Tectonic Therapeutic, Inc. (AVRO) Delisted | Grant (A) | — | $0 | EDGAR |
| 2020-04-08 | Cogent Biosciences, Inc. (UMRX) Delisted | Grant (A) | — | $0 | EDGAR |
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.