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Casdin Partners GP, LLC

CIK 1534260 · last filed 2026-05-21

Casdin Partners GP, LLC is a corporate insider who has filed 10 SEC Form 4 insider transactions across 3 companies since 2020. The most recent filing shows the insider sold $112.5M of BLFS on May 21, 2026. Across all open-market trades the lifetime net is +$2.3M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $473.9M across reported positions. The firm reports its address in New York, NY. 74 SEC filings were submitted jointly with Casdin Capital, LLC.

"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

$473.90M

Companies

3

Total Filings

10

Lifetime Open-Market Net

$2.28M

Filer Profile

Reported Address
1350 AVENUE OF THE AMERICAS
SUITE 1140
NEW YORK, NY 10019
Phone
(212) 300-5575
State of Incorporation
DE
Related Filers
Casdin Capital, LLC — 74 joint filings, latest 2026-06-08
Casdin Partners Master Fund, L.P. — 74 joint filings, latest 2026-06-08
Eli Casdin — 67 joint filings, latest 2026-06-08
Casdin Private Growth Equity Fund II GP, LLC — 28 joint filings, latest 2025-12-04
Casdin Private Growth Equity Fund II, L.P. — 28 joint filings, latest 2025-12-04
CASDIN PRIVATE GROWTH EQUITY FUND GP, LLC — 27 joint filings, latest 2025-12-04
Casdin Private Growth Equity Fund, L.P. — 27 joint filings, latest 2025-12-04
Casdin Amplify Fund, LP — 9 joint filings, latest 2025-03-04
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
BLFS 10%+ Owner 13,228,700 $34.95 $462.34M -$143.55M 4 2026-05-21
GeneDx Holdings Corp. (WGSWW) Delisted Director 3,202,681 $0.00 $641 $99.62M 2 2026-05-20
LAB Director 16,746,107 $0.69 $11.55M $46.21M 4 2025-03-04

Recent Filings

10 filings
Insider 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
2026-05-21 BLFS Sell (S) −4,800,000 -$112.50M EDGAR
2026-05-20 GeneDx Holdings Corp. (WGSWW) Delisted Buy (P) +2,000,000 $85.84M EDGAR
2025-06-12 BLFS Sell (S) −4,000,000 -$95.20M EDGAR
2025-03-04 LAB Mixed +43,912,566 $46.77M EDGAR
2025-03-04 LAB — — $0 EDGAR
2024-06-05 GeneDx Holdings Corp. (WGSWW) Delisted Buy (P) +650,000 $13.79M EDGAR
2024-01-09 LAB Grant (A) +111,925,952 $0 EDGAR
2023-05-23 BLFS Buy (P) +299,892 $6.69M EDGAR
2022-04-06 LAB Grant (A) — $0 EDGAR
2020-07-02 BLFS Buy (P) +3,962,332 $57.45M 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.