Western Digital Corporation
CH ˙ BRSE ˙ US9581021055
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT
SecurityCH:12355 / Western Digital Corporation
InstitutionWorldquant Millennium Advisors Llc
Latest Disclosed Ownership184,934 shares
Latest Disclosed Value $ 50,022,798
Worldquant Millennium Advisors Llc reports 71.19% decrease in ownership of 12355 / Western Digital Corporation

On May 15, 2026 - Worldquant Millennium Advisors Llc filed a 13F-HR form disclosing ownership of 184,934 shares of Western Digital Corporation (CH:12355) valued at $50,022,798 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 641,925 shares of Western Digital Corporation. This represents a change in shares of -71.19% 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)
2026-05-15 2026-03-31 13F WESTERN DIGITAL COM 958102105 184,934 -456,991 -71.19 50,023 -54.77 0.1929
2026-02-17 2025-12-31 13F WESTERN DIGITAL COM 958102105 641,925 -653,004 -50.43 110,584 -28.87 0.4290
2025-11-14 2025-09-30 13F WESTERN DIGITAL COM 958102105 1,294,929 958,289 284.66 155,469 621.74 0.6716
2025-08-14 2025-06-30 13F WESTERN DIGITAL COM 958102105 336,640 336,640 21,542 0.1070
2025-02-14 2024-12-31 13F WESTERN DIGITAL COM 958102105 0 -8,475 -100.00 0 -100.00
2024-11-14 2024-09-30 13F WESTERN DIGITAL COM 958102105 8,475 -296,199 -97.22 579 -97.50 0.0042
2024-08-14 2024-06-30 13F WESTERN DIGITAL COM 958102105 304,674 104,278 52.04 23,085 68.81 0.2105
2024-05-15 2024-03-31 13F WESTERN DIGITAL COM 958102105 200,396 -673,094 -77.06 13,675 -70.11 0.1687
2024-02-14 2023-12-31 13F WESTERN DIGITAL COM 958102105 873,490 596,837 215.73 45,745 262.39 0.6402
2023-11-14 2023-09-30 13F WESTERN DIGITAL COM 958102105 276,653 175,736 174.14 12,624 229.84 0.1949
2023-08-14 2023-06-30 13F WESTERN DIGITAL COM 958102105 100,917 100,917 3,828 0.0648
2022-08-15 2022-06-30 13F WESTERN DIGITAL COM 958102105 0 -56,021 -100.00 0 -100.00
2022-05-16 2022-03-31 13F WESTERN DIGITAL COM 958102105 56,021 30,206 117.01 2,781 65.24 0.0678
2022-02-14 2021-12-31 13F WESTERN DIGITAL COM 958102105 25,815 25,815 1,683 0.0335
2021-05-17 2021-03-31 13F WESTERN DIGITAL COM 958102105 0 -217,214 -100.00 0 -100.00
2021-02-16 2020-12-31 13F WESTERN DIGITAL COM 958102105 217,214 -6,338 -2.84 12,031 47.24 0.2630
2020-11-16 2020-09-30 13F WESTERN DIGITAL COM 958102105 223,552 -144,633 -39.28 8,171 -49.73 0.1936
2020-08-14 2020-06-30 13F WESTERN DIGITAL COM 958102105 368,185 -42,090 -10.26 16,255 -4.81 0.3741
2020-05-14 2020-03-31 13F WESTERN DIGITAL COM 958102105 410,275 410,275 17,076 0.4153
2019-02-14 2018-12-31 13F WESTERN DIGITAL COM 958102105 0 -115,003 -100.00 0 -100.00
2018-11-14 2018-09-30 13F WESTERN DIGITAL COM 958102105 115,003 -185,052 -61.67 6,732 -71.02 0.2255
2018-08-14 2018-06-30 13F WESTERN DIGITAL COM 958102105 300,055 300,055 23,227 0.8908
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.