SEC ownership of XBiotech Inc.

Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001626878.

Comparable stake leader

John Simard

Disclosed value leader

John Simard

Comparable rows

2/29

Latest evidence

26 Oct 2026

Ownership snapshot CIK-linked ownership evidence from parsed SEC filings. 3 signals
Comparable ownership rows
2 of 29
Meaning: Rows with safely comparable ownership %
Latest 13D/G holder
John Simard
Source: Latest parsed Schedule 13D/G stake
Latest parsed ownership date
26 Oct 2026
Freshness: Most recent filing date in this holder set
Issuer Names, identifiers, and filing context for this profile. 2 identity fields
Issuer CIK
0001626878
Issuer location
Austin, TX

Ownership snapshot

Top shareholders of XBiotech Inc. (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Comparable stake leader
John Simard
Disclosed value leader
John Simard
Comparable rows
2/29
Latest evidence
26 Oct 2026
13D/G 3/4/5 13F Lead comparable stake: 18% 27 rows are not safely comparable across share classes. 13D/G row: John Simard Showing 1-8 of 29 holder rows.

Quick read

John Simard leads the comparable SEC ownership view at 18%.

2 of 29 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.

Open SEC evidence Opens John Simard's linked filing trail.
Comparable ownership Top 2
John Simard 18%
W. Thorpe McKenzie 9.8%

Ownership % is shown only when SEC disclosures are safely comparable across share classes.

Detailed SEC evidence table Showing 1-8 of 29 holder rows
Holder Evidence Ownership % Position 12M Net Δ As of
John Simard
13D/G 3/4/5
Director, 10%+ Owner
18%
Reported 13D/G · 31 Dec 2025
$13,784,658
5,719,775 shares
-$2,180,460 31 Dec 2025
W. Thorpe McKenzie
13D/G 3/4/5
Director, 10%+ Owner
9.8%
Reported 13D/G · 31 Dec 2025
$7,245,084
3,006,259 shares
+$45,188 31 Dec 2025
Thomas Martin Kuendig
3/4/5
Director
—
mixed-class rows
$1,017,000
379,115 shares
mixed-class rows
— 01 Oct 2025
Craig Evan Rademaker
3/4/5
Director
—
mixed-class rows
$579,638
263,089 shares
mixed-class rows
— 01 Oct 2025
GEODE CAPITAL MANAGEMENT, LLC
13F
Company
13F
—
denominator unverified
$469,192
214,116 shares
— 30 Sep 2026
VANGUARD CAPITAL MANAGEMENT LLC
13F
Company
13F
—
denominator unverified
$438,399
200,182 shares
— 30 Sep 2026
RBF Capital, LLC
13F
Company
13F
—
denominator unverified
$434,717
198,501 shares
— 30 Sep 2026
Angela Hu
3/4/5
Principle Financial Officer
—
denominator unverified
$298,605
25,500 shares
— 10 Feb 2023
How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

Forms 3/4/5 flow

Insider trading overview

Net insider flow leans to buying over the last 12 months. Net value: +$854,660.

Buys
$854,660
Insiders: 1
Sells
$0
Insiders: 0
Net
+$854,660
Shares: +438,524
Window
Last 12 months
4 rolling buckets
Buy value Sell value
Shares: 438,524 Shares: 0
Window (months) Buy shares Sell shares Buy value Sell value Net value
0-3 438,524 0 $854,660 $0 +$854,660
3-6 0 0 $0 $0 $0
6-9 0 0 $0 $0 $0
9-12 0 0 $0 $0 $0

Reporting owners

Insider holders from Forms 3/4/5

Showing 1-13 of 13 reporting-owner rows connected to XBiotech Inc.. Open a relationship link for the CIK-to-CIK filing trail.

Rows
13
Largest Forms 3/4/5 holder
John Simard
Net 12M change
+$854.66KFull value: +$854,660 · USD · 12-month change
Latest report
03 Nov 2026
Name Relationship Holdings Value Past Year Net Change Change % Valuation Report Date
John Simard Director, 10%+ Owner $8,730,924 +$854,660 +11% Filing P/S 03 Nov 2026
Thomas Martin Kuendig Director $1,017,000 Mixed 01 Oct 2025
Craig Evan Rademaker Director $579,638 Mixed 01 Oct 2025
Angela Hu Principle Financial Officer $298,605 Mixed 10 Feb 2023
W. Thorpe McKenzie Director, 10%+ Owner Mixed 20 Jun 2024
Donald H. MacAdam Director Mixed 20 Jun 2024
Tevi David Troy Director Mixed 01 Oct 2025
David Spencer Soffer Director Mixed 01 Oct 2025
Peter Libby Director Mixed 20 Jun 2024
Jan-Paul Simard Co-Chief Executive Officer Mixed 26 Oct 2026
Queena Han VP Finance & HR Mixed 19 Nov 2021
Sushma Shivaswamy Chief Scientific Officer Mixed 10 Feb 2023
Jan-Paul Waldin Director Mixed 20 Jun 2024

Recent insider transactions for XBiotech Inc.

Showing up to 300 recent insider transactions from the last 12 months.

Insider Symbol Class Transaction % SEC-reported value SEC-reported price Shares Shares owned Date Ownership
John Simard XBIT Common Stock Purchase 1.67% $143,409 $2.05 70,000 4,261,690 03 Nov 2026 Direct
Jan-Paul Simard XBIT Stock Option Award 2,000,000 2,000,000 26 Oct 2026 Direct
John Simard XBIT Common Stock Purchase 9.64% $711,251 $1.93 368,524 4,191,690 26 Oct 2026 Direct
* marks a reported price that did not pass the local price check.
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