Western Digital Corporation
MX ˙ BMV ˙ US9581021055
SecurityMX:WDC / Western Digital Corporation
InstitutionSei Investments Co
Latest Disclosed Ownership471,197 shares
Latest Disclosed Value $ 81,170,986
Sei Investments Co reports 2.46% increase in ownership of WDC / Western Digital Corporation

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 471,197 shares of Western Digital Corporation (MX:WDC) valued at $81,170,986 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 459,874 shares of Western Digital Corporation. This represents a change in shares of 2.46% 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)
2026-02-13 2025-12-31 13F WESTERN DIGITAL COM 958102105 471,197 11,323 2.46 81,171 47.04 0.0801
2025-11-13 2025-09-30 13F WESTERN DIGITAL COM 958102105 459,874 358,136 352.02 55,201 747.94 0.0594
2025-08-14 2025-06-30 13F WESTERN DIGITAL COM 958102105 101,738 9,349 10.12 6,511 74.44 0.0075
2025-05-14 2025-03-31 13F/A-1 WESTERN DIGITAL COM 958102105 92,389 -34,155 -26.99 3,733 -50.56 0.0048
2025-05-13 2025-03-31 13F WESTERN DIGITAL COM 958102105 128,898 2,354 6,428 0.0070
2025-02-11 2024-12-31 13F WESTERN DIGITAL COM 958102105 126,544 -29,213 -18.76 7,549 -29.02 0.0097
2024-11-12 2024-09-30 13F WESTERN DIGITAL COM 958102105 155,757 -82,868 -34.73 10,635 -41.18 0.0138
2024-08-13 2024-06-30 13F WESTERN DIGITAL COM 958102105 238,625 -35,858 -13.06 18,081 -3.47 0.0256
2024-05-07 2024-03-31 13F WESTERN DIGITAL COM 958102105 274,483 17,288 6.72 18,730 39.06 0.0274
2024-02-14 2023-12-31 13F WESTERN DIGITAL COM 958102105 257,195 -27,270 -9.59 13,469 3.77 0.0216
2023-11-14 2023-09-30 13F WESTERN DIGITAL COM 958102105 284,465 23,099 8.84 12,980 30.94 0.0233
2023-08-11 2023-06-30 13F WESTERN DIGITAL COM 958102105 261,366 36,198 16.08 9,914 16.87 0.0173
2023-05-12 2023-03-31 13F WESTERN DIGITAL COM 958102105 225,168 19,575 9.52 8,482 30.77 0.0158
2023-02-10 2022-12-31 13F WESTERN DIGITAL COM 958102105 205,593 96,271 88.06 6,486 82.29 0.0144
2022-11-14 2022-09-30 13F WESTERN DIGITAL COM 958102105 109,322 66,432 154.89 3,558 89.26 0.0079
2022-08-15 2022-06-30 13F WESTERN DIGITAL COM 958102105 42,890 12,810 42.59 1,880 27.80 0.0041
2022-05-13 2022-03-31 13F WESTERN DIGITAL COM 958102105 30,080 -93,835 -75.73 1,471 -81.79 0.0030
2022-02-14 2021-12-31 13F WESTERN DIGITAL COM 958102105 123,915 90,378 269.49 8,080 329.10 0.0152
2021-11-12 2021-09-30 13F WESTERN DIGITAL COM 958102105 33,537 3,922 13.24 1,883 -10.46 0.0040
2021-08-06 2021-06-30 13F WESTERN DIGITAL COM 958102105 29,615 9,363 46.23 2,103 55.55 0.0047
2021-05-12 2021-03-31 13F WESTERN DIGITAL COM 958102105 20,252 -25,367 -55.61 1,352 -46.50 0.0034
2021-02-08 2020-12-31 13F WESTERN DIGITAL COM 958102105 45,619 -35,526 -43.78 2,527 -14.54 0.0065
2020-12-04 2020-09-30 13F/A-1 WESTERN DIGITAL COM 958102105 81,145 44,041 118.70 2,957 80.30 0.0086
2020-11-06 2020-09-30 13F WESTERN DIGITAL COM 958102105 82,812 45,708 3,018 7,266.6730
2020-08-17 2020-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 37,104 -21,089 -36.24 1,640 -32.37 0.0051
2020-08-11 2020-06-30 13F WESTERN DIGITAL COM 958102105 75,657 17,464 4,760 12,911.7534
2020-05-14 2020-03-31 13F WESTERN DIGITAL COM 958102105 58,193 -16,057 -21.63 2,425 -48.59 0.0089
2020-02-06 2019-12-31 13F WESTERN DIGITAL COM 958102105 74,250 17,751 31.42 4,717 39.97 0.0141
2019-11-12 2019-09-30 13F WESTERN DIGITAL COM 958102105 56,499 -101,169 -64.17 3,370 -55.05 0.0086
2019-08-14 2019-06-30 13F WESTERN DIGITAL COM 958102105 157,668 -32,388 -17.04 7,497 -17.70 0.0245
2019-05-15 2019-03-31 13F WESTERN DIGITAL COM 958102105 190,056 -137,918 -42.05 9,109 -49.10 0.0306
2019-02-13 2018-12-31 13F WESTERN DIGITAL COM 958102105 327,974 32,133 10.86 17,897 3.06 0.0637
2018-11-08 2018-09-30 13F WESTERN DIGITAL COM 958102105 295,841 -32,303 -9.84 17,366 -31.63 0.0629
2018-08-03 2018-06-30 13F WESTERN DIGITAL COM 958102105 328,144 -38,305 -10.45 25,401 -24.88 0.0863
2018-05-11 2018-03-31 13F WESTERN DIGITAL COM 958102105 366,449 28,317 8.37 33,812 25.74 0.1296
2018-02-08 2017-12-31 13F WESTERN DIGITAL COM 958102105 338,132 19,535 6.13 26,891 -2.31 0.0934
2017-11-06 2017-09-30 13F WESTERN DIGITAL COM 958102105 318,597 41,391 14.93 27,527 12.08 0.0978
2017-07-31 2017-06-30 13F WESTERN DIGITAL COM 958102105 277,206 37,084 15.44 24,560 23.93 0.0979
2017-05-05 2017-03-31 13F WESTERN DIGITAL COM 958102105 240,122 149,883 166.10 19,817 223.17 0.0868
2017-02-02 2016-12-31 13F WESTERN DIGITAL COM 958102105 90,239 58,342 182.91 6,132 228.97 0.0297
2016-11-04 2016-09-30 13F WESTERN DIGITAL COM 958102105 31,897 17,926 128.31 1,864 182.00 0.0095
2016-08-11 2016-06-30 13F WESTERN DIGITAL COM 958102105 13,971 -1,762 -11.20 661 -11.04 0.0040
2016-05-10 2016-03-31 13F/A-1 WESTERN DIGITAL COM 958102105 15,733 -42,452 -72.96 743 -78.73 0.0046
2016-02-03 2015-12-31 13F WESTERN DIGITAL COM 958102105 58,185 9,839 20.35 3,493 -9.06 0.0213
2015-11-02 2015-09-30 13F/A-1 WESTERN DIGITAL COM 958102105 48,346 -47,539 -49.58 3,841 -48.92 0.0353
2015-10-30 2015-09-30 13F WESTERN DIGITAL COM 958102105 48,346 3,841
2015-08-07 2015-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 95,885 1,646 1.75 7,519 -12.29 0.0680
2015-08-04 2015-06-30 13F WESTERN DIGITAL COM 958102105 95,885 1,646 7,519 0.0680
2015-05-14 2015-03-31 13F/A-1 WESTERN DIGITAL COM 958102105 94,239 5,893 6.67 8,573 -12.37 0.0744
2015-05-01 2015-03-31 13F WESTERN COPPER & GOLD COM 958102105 94,239 8,573
2015-02-10 2014-12-31 13F WESTERN DIGITAL COM 958102105 88,346 88,346 9,783 0.0865
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.