Beth C Seidenberg
CIK 1184592 · last filed 2026-08-10
"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.
TSRO 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
WESTLAKE VILLAGE, CA 91361
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| Latigo Biotherapeutics, Inc. (LTGO) Delisted | Director | 5,160,847 | $15.11 | $77.95M | $0 | 1 | 2026-08-10 |
| SGMT | Director | 84,768 | $10.26 | $869.7K | $750.0K | 4 | 2026-06-15 |
| KYTX | Director | 3,809,667 | $5.47 | $20.84M | $1000.0K | 4 | 2026-05-29 |
| VERA | Director | 135,565 | $29.59 | $4.01M | $2.90M | 21 | 2026-05-26 |
| ACELYRIN, Inc. (SLRN) Delisted | Director | 9,850,729 | $2.27 | $22.36M | $23.58M | 2 | 2024-06-11 |
| PGNY | Director | 271,322 | $27.84 | $7.55M | -$2.80M | 24 | 2024-05-28 |
| ATRA | Director | 4,636 | $8.45 | $39.2K | $0 | 15 | 2023-06-02 |
| Epizyme, Inc. (EPZM) Delisted | Director | 4,124,036 | $1.47 | $6.06M | -$10.74M | 11 | 2019-07-02 |
| ARMO BioSciences, Inc. (ARMO) Delisted | Director | 0 | — | — | $0 | 3 | 2018-06-22 |
| TESARO, Inc. (TSRO) Delisted | Director | 2,040,675 | — | — | $53.00M | 13 | 2018-06-05 |
| BCRX | Director | — | $7.99 | — | $0 | 4 | 2010-05-17 |
Recent Filings · Page 9 of 11
109 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2017-06-12 | ATRA | Grant (A) | +5,000 | $0 | EDGAR |
| 2017-06-05 | TESARO, Inc. (TSRO) Delisted | Grant (A) | +402 | $0 | EDGAR |
| 2017-01-05 | ATRA | Grant (A) | +2,000 | $0 | EDGAR |
| 2016-07-06 | Epizyme, Inc. (EPZM) Delisted | Grant (A) | +3,200 | $33.1K | EDGAR |
| 2016-06-03 | TESARO, Inc. (TSRO) Delisted | Grant (A) | +1,269 | $0 | EDGAR |
| 2016-05-23 | Epizyme, Inc. (EPZM) Delisted | Grant (A) | — | $0 | EDGAR |
| 2016-03-18 | TESARO, Inc. (TSRO) Delisted | Buy (P) | +1,420,858 | $50.00M | EDGAR |
| 2016-02-17 | TESARO, Inc. (TSRO) Delisted | Other (J) | −8,337 | $0 | EDGAR |
| 2016-01-05 | ATRA | Grant (A) | — | $0 | EDGAR |
| 2015-12-17 | ATRA | Other (J) | −1,720 | $0 | 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.