Casdin Partners Master Fund, L.P.
CIK 1534265 · last filed 2025-12-04
"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
$585.08M
Companies
5
Total Filings
15
Lifetime Open-Market Net
-$38.56M
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 |
|---|---|---|---|---|---|---|---|
| LAB | Director | 74,851,062 | $0.67 | $50.27M | $15.02M | 2 | 2025-12-04 |
| BLFS | 10%+ Owner | 14,664,330 | $36.47 | $534.81M | -$85.64M | 2 | 2025-10-17 |
| 2seventy bio, Inc. (TSVT) Delisted | Director | 2,016,600 | $5.00 | $10.08M | $816.0K | 1 | 2024-03-28 |
| Verve Therapeutics, Inc. (VERV) Delisted | 10%+ Owner | 1,007,311 | $11.13 | $11.21M | $20.90M | 1 | 2021-06-22 |
| Decibel Therapeutics, Inc. (DBTX) Delisted | 10%+ Owner | 546,421 | $4.91 | $2.68M | $10.35M | 1 | 2021-02-19 |
Recent Filings · Page 2 of 2
15 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 |
|---|---|---|---|---|---|
| 2025-06-10 | BLFS | Notice (144) | −1,000,000 | -$23.91M | EDGAR |
| 2024-05-02 | BLFS | Other (J) | — | $0 | EDGAR |
| 2024-03-28 | 2seventy bio, Inc. (TSVT) Delisted | Buy (P) | +160,000 | $816.0K | EDGAR |
| 2021-06-22 | Verve Therapeutics, Inc. (VERV) Delisted | Mixed | +2,417,596 | $20.90M | EDGAR |
| 2021-02-19 | Decibel Therapeutics, Inc. (DBTX) Delisted | Mixed | +1,121,421 | $10.35M | EDGAR |
Showing 11–15 of 15
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Page 2 of 2
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.