Western Digital Corporation
CH ˙ BRSE ˙ US9581021055
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT
SecurityCH:12355 / Western Digital Corporation
InstitutionDimensional Fund Advisors Lp
Latest Disclosed Ownership2,503,321 shares
Latest Disclosed Value $ 676,753,232
Dimensional Fund Advisors Lp reports 29.79% decrease in ownership of 12355 / Western Digital Corporation

On May 7, 2026 - Dimensional Fund Advisors Lp filed a 13F-HR form disclosing ownership of 2,503,321 shares of Western Digital Corporation (CH:12355) valued at $676,753,232 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 3,565,342 shares of Western Digital Corporation. This represents a change in shares of -29.79% during the quarter.

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.

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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)
2026-05-07 2026-03-31 13F WESTERN DIGITAL COM 958102105 2,503,321 -1,062,021 -29.79 676,753 10.16 0.1406
2026-02-12 2025-12-31 13F WESTERN DIGITAL COM 958102105 3,565,342 -239,565 -6.30 614,316 34.50 0.1289
2025-11-12 2025-09-30 13F WESTERN DIGITAL COM 958102105 3,804,907 402,981 11.85 456,737 109.82 0.0980
2025-08-12 2025-06-30 13F WESTERN DIGITAL COM 958102105 3,401,926 468,648 15.98 217,676 83.58 0.0504
2025-05-13 2025-03-31 13F WESTERN DIGITAL COM 958102105 2,933,278 216,387 7.96 118,574 -26.82 0.0295
2025-02-13 2024-12-31 13F WESTERN DIGITAL COM 958102105 2,716,891 -182,694 -6.30 162,021 -18.19 0.0389
2024-11-07 2024-09-30 13F WESTERN DIGITAL COM 958102105 2,899,585 17,738 0.62 198,048 -9.32 0.0480
2024-08-09 2024-06-30 13F WESTERN DIGITAL COM 958102105 2,881,847 143,074 5.22 218,400 16.86 0.0570
2024-05-10 2024-03-31 13F WESTERN DIGITAL COM 958102105 2,738,773 -375,022 -12.04 186,894 14.60 0.0506
2024-02-07 2023-12-31 13F WESTERN DIGITAL COM 958102105 3,113,795 -91,973 -2.87 163,086 11.48 0.0476
2023-11-09 2023-09-30 13F WESTERN DIGITAL COM 958102105 3,205,768 -213,371 -6.24 146,295 12.81 0.0480
2023-08-09 2023-06-30 13F WESTERN DIGITAL COM 958102105 3,419,139 11,313 0.33 129,687 1.03 0.0413
2023-05-12 2023-03-31 13F WESTERN DIGITAL COM 958102105 3,407,826 -134,217 -3.79 128,365 115,544.14 0.0432
2023-02-09 2022-12-31 13F WESTERN DIGITAL COM 958102105 3,542,043 -133,486 -3.63 112 -99.91 0.0330
2022-11-10 2022-09-30 13F WESTERN DIGITAL COM 958102105 3,675,529 162,535 4.63 119,635 -24.03 0.0459
2022-08-12 2022-06-30 13F WESTERN DIGITAL COM 958102105 3,512,994 11,151 0.32 157,482 -9.44 0.0565
2022-05-13 2022-03-31 13F WESTERN DIGITAL COM 958102105 3,501,843 80,373 2.35 173,893 -22.06 0.0536
2022-02-09 2021-12-31 13F WESTERN DIGITAL COM 958102105 3,421,470 15,437 0.45 223,112 16.05 0.0675
2021-11-12 2021-09-30 13F WESTERN DIGITAL COM 958102105 3,406,033 5,820 0.17 192,249 -20.55 0.0619
2021-08-12 2021-06-30 13F WESTERN DIGITAL COM 958102105 3,400,213 133,831 4.10 241,978 11.00 0.0766
2021-05-14 2021-03-31 13F WESTERN DIGITAL COM 958102105 3,266,382 97,751 3.08 218,003 24.31 0.0721
2021-03-08 2020-12-31 13F/A-2 WESTERN DIGITAL COM 958102105 3,168,631 72,906 2.36 175,375 54.92 0.0633
2021-02-11 2020-12-31 13F WESTERN DIGITAL COM 958102105 3,168,631 72,906 175,375 63,336.1283
2020-11-12 2020-09-30 13F WESTERN DIGITAL COM 958102105 3,095,725 3,665 0.12 113,206 -17.05 0.0480
2020-08-13 2020-06-30 13F WESTERN DIGITAL COM 958102105 3,092,060 15,219 0.49 136,471 6.54 0.0600
2020-05-14 2020-03-31 13F WESTERN DIGITAL COM 958102105 3,076,841 -473,991 -13.35 128,089 -43.16 0.0667
2020-02-14 2019-12-31 13F WESTERN DIGITAL COM 958102105 3,550,832 -376,753 -9.59 225,337 -3.82 0.0821
2019-11-12 2019-09-30 13F WESTERN DIGITAL COM 958102105 3,927,585 100,516 2.63 234,280 28.82 0.0910
2019-08-13 2019-06-30 13F WESTERN DIGITAL COM 958102105 3,827,069 511,316 15.42 181,871 14.18 0.0706
2019-08-12 2019-03-31 13F/A-2 WESTERN DIGITAL COM 958102105 3,315,753 210,910 6.79 159,282 38.76 0.0634
2019-05-10 2019-03-31 13F WESTERN DIGITAL COM 958102105 3,315,753 210,910 159,282
2019-02-26 2018-12-31 13F/A-1 WESTERN DIGITAL COM 958102105 3,104,843 43,310 1.41 114,788 -35.95 0.0520
2019-02-13 2018-12-31 13F WESTERN DIGITAL COM 958102105 3,104,843 43,310 114,788
2018-11-13 2018-09-30 13F WESTERN DIGITAL COM 958102105 3,061,533 697 0.02 179,211 -24.36 0.0682
2018-08-10 2018-06-30 13F WESTERN DIGITAL COM 958102105 3,060,836 49,960 1.66 236,931 -14.72 0.0945
2018-05-11 2018-03-31 13F WESTERN DIGITAL COM 958102105 3,010,876 9,662 0.32 277,814 16.37 0.1158
2018-02-12 2017-12-31 13F WESTERN DIGITAL COM 958102105 3,001,214 -85,711 -2.78 238,731 -10.49 0.0990
2017-11-13 2017-09-30 13F WESTERN DIGITAL COM 958102105 3,086,925 83,030 2.76 266,720 0.18 0.1166
2017-08-11 2017-06-30 13F WESTERN DIGITAL COM 958102105 3,003,895 24,920 0.84 266,233 8.28 0.1229
2017-05-12 2017-03-31 13F WESTERN DIGITAL COM 958102105 2,978,975 7,910 0.27 245,876 21.78 0.1175
2017-02-09 2016-12-31 13F WESTERN DIGITAL COM 958102105 2,971,065 477,939 19.17 201,898 38.50 0.1008
2016-11-10 2016-09-30 13F WESTERN DIGITAL COM 958102105 2,493,126 607,294 32.20 145,770 63.62 0.0788
2016-08-09 2016-06-30 13F WESTERN DIGITAL COM 958102105 1,885,832 173,658 10.14 89,093 10.18 0.0513
2016-05-13 2016-03-31 13F WESTERN DIGITAL COM 958102105 1,712,174 47,815 2.87 80,864 -19.11 0.0484
2016-02-10 2015-12-31 13F WESTERN DIGITAL COM 958102105 1,664,359 50,051 3.10 99,963 -21.96 0.0623
2015-11-13 2015-09-30 13F WESTERN DIGITAL COM 958102105 1,614,308 69,150 4.48 128,084 5.65 0.0841
2015-08-14 2015-06-30 13F WESTERN DIGITAL COM 958102105 1,545,158 124,112 8.73 121,234 -6.27 0.0742
2015-05-14 2015-03-31 13F WESTERN DIGITAL COM 958102105 1,421,046 -132,303 -8.52 129,346 -24.79 0.0817
2015-02-06 2014-12-31 13F WESTERN DIGITAL COM 958102105 1,553,349 -61,520 -3.81 171,985 9.44 0.1130
2014-11-13 2014-09-30 13F WESTERN DIGITAL COM 958102105 1,614,869 -67,652 -4.02 157,149 1.19 0.1113
2014-08-08 2014-06-30 13F WESTERN DIGITAL COM 958102105 1,682,521 -154 -0.01 155,303 0.54 0.1080
2014-05-14 2014-03-31 13F WESTERN DIGITAL COM 958102105 1,682,675 -12,468 -0.74 154,474 8.62 0.1154
2014-02-12 2013-12-31 13F WESTERN DIGITAL COM 958102105 1,695,143 -407,131 -19.37 142,217 6.71 0.1108
2013-11-13 2013-09-30 13F WESTERN DIGITAL COM 958102105 2,102,274 40,219 1.95 133,272 4.08 0.1153
2013-08-15 2013-06-30 13F WESTERN DIGITAL COM 958102105 2,062,055 2,062,055 128,044 0.1206
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.