Biotechnology Value Trading Fund OS LP

CIK 1660683 · last filed 2025-05-20

Biotechnology Value Trading Fund OS LP is a corporate insider who has filed 20 SEC Form 4 insider transactions across 14 companies since 2017. The most recent filing shows the insider sold $106.4M of XOMAP on May 20, 2025. Across all open-market trades the lifetime net is −$1.22B, making them a net seller over the disclosed history. Current disclosed insider exposure totals $442.2M across reported positions. The firm reports its address in Grand Cayman, E9. 237 SEC filings were submitted jointly with BIOTECHNOLOGY VALUE FUND II LP.

"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

$442.17M

Companies

14

Total Filings

20

Lifetime Open-Market Net

-$1.22B

Filer Profile

Reported Address
P.O. BOX 309 UGLAND HOUSE
GRAND CAYMAN, E9 KY1-1104
Phone
(415) 525-8890
State of Incorporation
Cayman Islands
Related Filers
BIOTECHNOLOGY VALUE FUND II LP — 237 joint filings, latest 2026-07-16
BIOTECHNOLOGY VALUE FUND L P — 237 joint filings, latest 2026-07-16
BVF INC/IL — 237 joint filings, latest 2026-07-16
BVF PARTNERS L P/IL — 237 joint filings, latest 2026-07-16
BVF Partners OS Ltd. — 237 joint filings, latest 2026-07-16
MARK N LAMPERT — 237 joint filings, latest 2026-07-16
BVF GP HOLDINGS LLC — 155 joint filings, latest 2026-07-16
BVF I GP LLC — 155 joint filings, latest 2026-07-16
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
XOMA Royalty Corp (XOMAP) Delisted 1,322,758 $24.98 $33.04M -$106.43M 1 2025-05-20
KYMR Director 1,888,351 $114.96 $217.08M $0 1 2023-06-20
GPCR 0 $38.66 $0 $0 1 2023-05-12
Repare Therapeutics Inc. (RPTX) Delisted 3,299,906 $2.65 $8.74M $18.99M 1 2022-06-15
CGEM 364,161 $20.59 $7.50M $82.65M 1 2022-06-03
CTI BIOPHARMA CORP (CTIC) Delisted 3,102,435 $9.09 $28.20M $50.00M 2 2021-04-05
Merus N.V. (MRUS) Delisted 3,513,335 $90.00 $316.20M $209.06M 1 2021-01-25
CYTK 2,777,320 $73.77 $204.88M $0 1 2020-11-20
FIVE PRIME THERAPEUTICS, INC. (FPRX) Delisted 670,695 $38.00 $25.49M -$1.49B 2 2020-11-13
CRESCENT BIOPHARMA, INC. (GLYC) Delisted 32,062 $15.70 $503.4K $25.65M 1 2020-11-03
XOMA Royalty Corp (XOMA) Delisted 2,022,816 $40.17 $81.26M $4.31M 3 2020-09-10
CONCERT PHARMACEUTICALS, INC. (CNCE) Delisted 952,859 $8.37 $7.98M -$28.94M 1 2019-06-12
XENE 216,694 $58.65 $12.71M $0 1 2018-03-29
INFINITY PHARMACEUTICALS, INC. (INFI) Delisted 2,968,487 $0.04 $132.7K $14.06M 1 2017-10-05

Recent Filings

20 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
2025-05-20 XOMA Royalty Corp (XOMAP) Delisted Sell (S) −3,927,230 -$106.43M EDGAR
2025-05-19 Disp (D) −163,128,720 $0
2023-06-28 Mixed −88,561,600 -$805.91M
2023-06-20 KYMR Grant (A) $0 EDGAR
2023-05-12 GPCR Other (J) −74,105,180 $0 EDGAR
2022-06-15 Repare Therapeutics Inc. (RPTX) Delisted Buy (P) +1,491,610 $18.99M EDGAR
2022-06-03 CGEM Buy (P) +7,513,960 $82.65M EDGAR
2021-04-05 CTI BIOPHARMA CORP (CTIC) Delisted Buy (P) +20,000,000 $50.00M EDGAR
2021-03-12 CTI BIOPHARMA CORP (CTIC) Delisted Grant (A) $0 EDGAR
2021-01-25 Merus N.V. (MRUS) Delisted Buy (P) +8,446,800 $209.06M EDGAR
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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.