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EcoR1 Capital, LLC

Position in XNCR — Xencor Inc

CIK 1587114 San Francisco, CA

Position in XNCR

as of Mar 31, 2026 · filed May 15, 2026
Position Value
$26,326,980
-$23,447,544 QoQ
Shares Held
2,183,000
-32.9% QoQ
Ownership
2.94%
of shares outstanding
% of Portfolio
1.25%
of 13F equity value
Holder Rank
not a current holder
Holding Since
Mar 2020
25 quarters on record
Voting authority Sole 100% Shared 0% None 0%

Common Shares in XNCR Over Time

Shares Held

Position Value (USD)

Derivatives in XNCR

reported options exposure · as of Dec 31, 2025
CallValue
$1,033,425
CallShares
67,500
PutValue
$0
PutShares
0

Notional value of option positions as reported on Form 13F. Calls and puts are disclosed separately and do not net against the common-share stake above.

Position in Biotechnology

Healthcare · as of Jun 30, 2026

EcoR1 Capital, LLC holds $1,935,887,028 across 29 Biotechnology names.

# Ticker Company Shares Value (USD) Open

All Filings in XNCR

Export CSV
26 filing rows on record
Report Date Value (USD) Shares
2026-03-31 $26,326,980 2,183,000
2025-12-31 $1,033,425 67,500
2025-12-31 $49,774,524 3,251,112
2025-09-30 $72,078,116 6,144,767
2025-06-30 $48,297,868 6,144,767
2025-03-31 $65,380,320 6,144,767
2024-12-31 $141,206,745 6,144,767
2024-09-30 $107,194,665 5,330,416
2024-06-30 $100,904,774 5,330,416
2024-03-31 $117,962,106 5,330,416
2023-12-31 $112,147,814 5,282,516
2023-09-30 $106,442,697 5,282,516
2023-06-30 $131,904,424 5,282,516
2023-03-31 $147,329,371 5,282,516
2022-12-31 $137,556,716 5,282,516
2022-09-30 $137,239,765 5,282,516
2022-06-30 $144,579,725 5,282,416
2022-03-31 $132,566,410 4,968,756
2021-12-31 $196,832,972 4,906,106
2021-09-30 $160,233,421 4,906,106
2021-06-30 $169,211,595 4,906,106
2021-03-31 $211,007,176 4,900,306
2020-12-31 $198,388,751 4,547,072
2020-09-30 $176,380,922 4,547,072
2020-06-30 $147,279,662 4,547,072
2020-03-31 $74,746,523 2,501,557