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Parallax Volatility Advisers, L.P.

Position in BIIB — Biogen Inc.

CIK 1521001 San Francisco, CA

Position in BIIB

as of Jun 30, 2026 · filed Aug 14, 2026
Position Value
$494,993
+$185,349 QoQ
Shares Held
2,291
+35.6% QoQ
Ownership
0.002%
of shares outstanding
% of Portfolio
0.02%
of 13F equity value
Holder Rank
#575
of 1,036 holders
Holding Since
Mar 2020
22 quarters on record
Voting authority Sole 100% Shared 0% None 0%

Common Shares in BIIB Over Time

Shares Held

Position Value (USD)

Derivatives in BIIB

reported options exposure · as of Sep 30, 2025
CallValue
$1,050,600
CallShares
7,500
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 Drug Manufacturers - General

Healthcare · as of Jun 30, 2026

Parallax Volatility Advisers, L.P. holds $35,775,129 across 10 Drug Manufacturers - General names. BIIB ranks #8 (1.4% of the industry book) .

# Ticker Company Shares Value (USD) Open
8 BIIB
Biogen Inc.
This page
2,291 $494,993

All Filings in BIIB

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47 filing rows on record
Report Date Value (USD) Shares
2026-06-30 $494,993 2,291
2026-03-31 $309,644 1,689
2025-12-31 $393,689 2,237
2025-09-30 $1,050,600 7,500
2024-12-31 $2,093,474 13,690
2024-09-30 $38,768 200
2024-09-30 $2,788,969 14,388
2024-06-30 $3,307,144 14,266
2023-09-30 $6,367,422 24,775
2023-09-30 $7,016,373 27,300
2023-09-30 $719,628 2,800
2023-06-30 $797,580 2,800
2023-06-30 $4,247,398 14,911
2023-06-30 $10,425,510 36,600
2023-03-31 $3,391,966 12,200
2022-12-31 $28,827,372 104,100
2022-12-31 $9,415,280 34,000
2022-09-30 $16,554,000 62,000
2022-09-30 $31,292,400 117,200
2022-06-30 $6,566,868 32,200
2022-06-30 $1,488,762 7,300
2022-03-31 $105,300 500
2022-03-31 $10,361,520 49,200
2022-03-31 $4,828,215 22,926
2021-12-31 $46,579,508 194,146
2021-12-31 $66,601,792 277,600
2021-12-31 $19,865,376 82,800
2021-09-30 $55,833,927 197,300
2021-09-30 $26,402,967 93,300
2021-09-30 $21,523,653 76,058
2021-06-30 $42,106,432 121,600
2021-06-30 $4,582,883 13,235
2021-06-30 $21,676,502 62,600
2021-03-31 $6,993,750 25,000
2021-03-31 $67,699 242
2020-12-31 $8,790,474 35,900
2020-12-31 $12,218,514 49,900
2020-12-31 $399,121 1,630
2020-09-30 $13,049,280 46,000
2020-09-30 $4,420,869 15,584
2020-09-30 $9,815,328 34,600
2020-06-30 $13,431,010 50,200
2020-06-30 $3,531,660 13,200
2020-06-30 $4,988,737 18,646
2020-03-31 $11,041,662 34,900
2020-03-31 $411,294 1,300
2020-03-31 $2,343,426 7,407