XBiotech Inc.
US ˙ NasdaqGS ˙ CA98400H1029

SecurityXBIT / XBiotech Inc.
InstitutionState Street Corp
Latest Disclosed Ownership73,006 shares
Latest Disclosed Value $ 171,564
State Street Corp ownership in XBIT / XBiotech Inc.

On May 15, 2026 - State Street Corp filed a 13F-HR form disclosing ownership of 73,006 shares of XBiotech Inc. (US:XBIT) valued at $171,564 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 73,006 shares of XBiotech Inc.. This represents a change in shares of 0.00% during the quarter. The current value of the position is $174,484 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

Upgrade to unlock premium data and export to Excel .

Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F XBIOTECH COM 98400H102 73,006 0 0.00 172 -1.72 0.0000
2026-02-13 2025-12-31 13F XBIOTECH COM 98400H102 73,006 5,700 8.47 174 -2.79 0.0000
2025-11-14 2025-09-30 13F XBIOTECH COM 98400H102 67,306 -1,220 -1.78 179 -11.82 0.0000
2025-08-14 2025-06-30 13F XBIOTECH COM 98400H102 68,526 -161,169 -70.17 204 -72.72 0.0000
2025-05-15 2025-03-31 13F XBIOTECH COM 98400H102 229,695 0 0.00 744 -17.97 0.0000
2025-02-14 2024-12-31 13F XBIOTECH COM 98400H102 229,695 5,100 2.27 907 -47.75 0.0000
2024-11-14 2024-09-30 13F XBIOTECH COM 98400H102 224,595 21,752 10.72 1,736 66.60 0.0001
2024-08-14 2024-06-30 13F XBIOTECH COM 98400H102 202,843 146,317 258.85 1,043 127.02 0.0000
2024-05-15 2024-03-31 13F XBIOTECH COM 98400H102 56,526 0 0.00 460 103.10 0.0000
2024-02-14 2023-12-31 13F XBIOTECH COM 98400H102 56,526 0 0.00 226 -2.59 0.0000
2023-11-14 2023-09-30 13F XBIOTECH COM 98400H102 56,526 0 0.00 233 -30.75 0.0000
2023-08-14 2023-06-30 13F XBIOTECH COM 98400H102 56,526 -769 -1.34 336 70.05 0.0000
2023-05-15 2023-03-31 13F XBIOTECH COM 98400H102 57,295 0 0.00 198 -1.99 0.0000
2023-05-15 2022-12-31 13F/A-99 XBIOTECH COM 98400H102 57,295 0 0.00 201 -2.90 0.0000
2023-05-15 2022-12-31 13F XBIOTECH COM 98400H102 57,295 0 201 0.0000
2022-11-15 2022-09-30 13F XBIOTECH COM 98400H102 57,295 -423 -0.73 207 -36.31 0.0000
2022-08-15 2022-06-30 13F XBIOTECH COM 98400H102 57,718 -266,252 -82.18 325 -88.39 0.0000
2022-05-16 2022-03-31 13F XBIOTECH COM 98400H102 323,970 -114,887 -26.18 2,799 -42.69 0.0001
2022-02-14 2021-12-31 13F XBIOTECH COM 98400H102 438,857 3,267 0.75 4,884 -13.42 0.0002
2021-11-15 2021-09-30 13F XBIOTECH COM 98400H102 435,590 26,836 6.57 5,641 -16.66 0.0003
2021-08-16 2021-06-30 13F XBIOTECH COM 98400H102 408,754 23,414 6.08 6,769 2.31 0.0004
2021-07-09 2021-03-31 13F/A-1 XBIOTECH COM 98400H102 385,340 110,430 40.17 6,616 53.79 0.0004
2021-05-17 2021-03-31 13F XBIOTECH COM 98400H102 385,340 110,430 6,616 0.0004
2021-02-16 2020-12-31 13F XBIOTECH COM 98400H102 274,910 2,730 1.00 4,302 -17.21 0.0003
2020-11-10 2020-09-30 13F XBIOTECH COM 98400H102 272,180 -3,050 -1.11 5,196 37.72 0.0004
2020-08-14 2020-06-30 13F XBIOTECH COM 98400H102 275,230 8,761 3.29 3,773 33.32 0.0003
2020-06-19 2020-03-31 13F/A-1 XBIOTECH COM 98400H102 266,469 -69,010 -20.57 2,830 -54.81 0.0002
2020-05-11 2020-03-31 13F XBIOTECH COM 98400H102 266,469 -69,010 2,830 248.5310
2020-02-06 2019-12-31 13F XBIOTECH COM 98400H102 335,479 -16,105 -4.58 6,262 70.26 0.0004
2019-11-14 2019-09-30 13F XBIOTECH COM 98400H102 351,584 76,556 27.84 3,678 76.40 0.0003
2019-08-14 2019-06-30 13F XBIOTECH COM 98400H102 275,028 252,214 1,105.52 2,085 730.68 0.0002
2019-05-15 2019-03-31 13F XBIOTECH COM 98400H102 22,814 -345 -1.49 251 112.71 0.0000
2019-02-12 2018-12-31 13F XBIOTECH COM 98400H102 23,159 -398 -1.69 118 57.33 0.0000
2018-11-09 2018-09-30 13F XBIOTECH Common equity shares 98400H102 23,557 -1,855 -7.30 75 -34.21 0.0000
2018-08-14 2018-06-30 13F XBIOTECH Common equity shares 98400H102 25,412 -291,314 -91.98 114 -93.29 0.0000
2018-05-15 2018-03-31 13F XBIOTECH Common equity shares 98400H102 316,726 8,205 2.66 1,698 39.64 0.0001
2018-02-14 2017-12-31 13F XBIOTECH Common equity shares 98400H102 308,521 -2,379 -0.77 1,216 -10.32 0.0001
2017-11-14 2017-09-30 13F XBIOTECH Common equity shares 98400H102 310,900 1,153 0.37 1,356 -6.80 0.0001
2017-08-14 2017-06-30 13F XBIOTECH Common equity shares 98400H102 309,747 23,412 8.18 1,455 -69.18 0.0001
2017-05-15 2017-03-31 13F XBIOTECH Common equity shares 98400H102 286,335 437 0.15 4,721 63.19 0.0004
2017-02-09 2016-12-31 13F XBIOTECH Common equity shares 98400H102 285,898 18,352 6.86 2,893 -19.59 0.0003
2017-01-13 2016-09-30 13F/A-1 XBIOTECH Common equity shares 98400H102 267,546 20,668 8.37 3,598 -30.33 0.0004
2016-11-14 2016-09-30 13F XBIOTECH Common equity shares 98400H102 267,546 3,598
2016-08-12 2016-06-30 13F XBIOTECH Common equity shares 98400H102 246,878 206,318 508.67 5,164 1,248.30 0.0006
2016-05-20 2016-03-31 13F/A-1 XBIOTECH Common equity shares 98400H102 40,560 14,290 54.40 383 34.39 0.0000
2016-05-12 2016-03-31 13F XBIOTECH Common equity shares 98400H102 40,560 383
2016-02-16 2015-12-31 13F XBIOTECH Common equity shares 98400H102 26,270 2,800 11.93 285 -18.34 0.0000
2015-11-16 2015-09-30 13F XBIOTECH Common equity shares 98400H102 23,470 2,185 10.27 349 -9.11 0.0000
2015-08-13 2015-06-30 13F XBIOTECH Common equity shares 98400H102 21,285 21,285 384 0.0000
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.