Western Digital Corporation
CH ˙ BRSE ˙ US9581021055
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT
SecurityCH:12355 / Western Digital Corporation
InstitutionAdvisors Asset Management, Inc.
Latest Disclosed Ownership5,057 shares
Latest Disclosed Value $ 1,367,868
Advisors Asset Management, Inc. reports 66.90% increase in ownership of 12355 / Western Digital Corporation

On May 15, 2026 - Advisors Asset Management, Inc. filed a 13F-HR form disclosing ownership of 5,057 shares of Western Digital Corporation (CH:12355) valued at $1,367,868 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 3,030 shares of Western Digital Corporation. This represents a change in shares of 66.90% 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 5,057 2,027 66.90 1,368 162.38 0.0227
2026-02-12 2025-12-31 13F WESTERN DIGITAL COM 958102105 3,030 799 35.81 522 95.13 0.0088
2025-11-06 2025-09-30 13F WESTERN DIGITAL COM 958102105 2,231 253 12.79 268 111.90 0.0045
2025-08-12 2025-06-30 13F WESTERN DIGITAL COM 958102105 1,978 -81 -3.93 127 51.81 0.0023
2025-05-15 2025-03-31 13F WESTERN DIGITAL COM 958102105 2,059 299 16.99 83 -20.19 0.0016
2025-02-10 2024-12-31 13F WESTERN DIGITAL COM 958102105 1,760 342 24.12 105 8.33 0.0019
2024-11-08 2024-09-30 13F WESTERN DIGITAL COM 958102105 1,418 344 32.03 97 18.52 0.0018
2024-08-14 2024-06-30 13F WESTERN DIGITAL COM 958102105 1,074 404 60.30 81 80.00 0.0016
2024-05-14 2024-03-31 13F WESTERN DIGITAL COM 958102105 670 474 241.84 46 350.00 0.0009
2024-02-14 2023-12-31 13F WESTERN DIGITAL COM 958102105 196 196 10 0.0002
2023-05-12 2023-03-31 13F WESTERN DIGITAL COM 958102105 0 -2,190 -100.00 0 -100.00
2023-02-13 2022-12-31 13F WESTERN DIGITAL COM 958102105 2,190 2,190 69 0.0014
2022-05-17 2022-03-31 13F WESTERN DIGITAL COM 958102105 0 -3,132 -100.00 0 -100.00
2022-02-15 2021-12-31 13F WESTERN DIGITAL COM 958102105 3,132 -5,299 -62.85 204 -57.14 0.0029
2021-11-12 2021-09-30 13F WESTERN DIGITAL COM 958102105 8,431 -7,717 -47.79 476 -58.57 0.0072
2021-07-30 2021-06-30 13F WESTERN DIGITAL COM 958102105 16,148 -10,689 -39.83 1,149 -35.85 0.0169
2021-05-07 2021-03-31 13F WESTERN DIGITAL COM 958102105 26,837 -57,112 -68.03 1,791 -61.48 0.0278
2021-02-12 2020-12-31 13F WESTERN DIGITAL COM 958102105 83,949 -50,697 -37.65 4,650 -5.51 0.0769
2020-11-16 2020-09-30 13F WESTERN DIGITAL COM 958102105 134,646 -70,785 -34.46 4,921 -45.74 0.0910
2020-08-12 2020-06-30 13F WESTERN DIGITAL COM 958102105 205,431 -65,184 -24.09 9,070 -19.47 0.1766
2020-05-15 2020-03-31 13F WESTERN DIGITAL COM 958102105 270,615 -65,986 -19.60 11,263 -47.28 0.2679
2020-05-20 2019-12-31 13F/A-1 WESTERN DIGITAL COM 958102105 336,601 -18,371 -5.18 21,364 0.91 0.3746
2020-02-14 2019-12-31 13F WESTERN DIGITAL COM 958102105 336,601 -18,371 21,364 189,091.5991
2019-11-14 2019-09-30 13F WESTERN DIGITAL COM 958102105 354,972 49,829 16.33 21,171 45.91 0.3899
2019-11-14 2019-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 305,143 79,628 35.31 14,510 33.88 0.2617
2019-08-14 2019-06-30 13F WESTERN DIGITAL COM 958102105 305,143 79,628 14,510
2019-05-15 2019-03-31 13F WESTERN DIGITAL COM 958102105 225,515 84,604 60.04 10,838 108.06 0.1929
2019-02-06 2018-12-31 13F/A-1 WESTERN DIGITAL COM 958102105 140,911 73,443 108.86 5,209 31.87 0.1049
2019-01-31 2018-12-31 13F WESTERN DIGITAL COM 958102105 140,911 73,443 5,209
2018-11-15 2018-09-30 13F WESTERN DIGITAL COM 958102105 67,468 38,484 132.78 3,950 76.02 0.0646
2018-08-22 2018-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 28,984 -7,697 -20.98 2,244 -29.72 0.0381
2018-08-15 2018-06-30 13F WESTERN DIGITAL COM 958102105 6,579 -30,102 2,244
2018-05-15 2018-03-31 13F WESTERN DIGITAL COM 958102105 36,681 -6,423 -14.90 3,193 -6.86 0.0535
2018-02-13 2017-12-31 13F WESTERN DIGITAL COM 958102105 43,104 -96,853 -69.20 3,428 -71.65 0.0563
2017-11-07 2017-09-30 13F WESTERN DIGITAL COM 958102105 139,957 -102,283 -42.22 12,092 -43.66 0.2026
2017-08-02 2017-06-30 13F WESTERN DIGITAL COM 958102105 242,240 -78,756 -24.53 21,462 -18.99 0.3587
2017-05-02 2017-03-31 13F WESTERN DIGITAL COM 958102105 320,996 33,211 11.54 26,492 57.44 0.4440
2016-10-31 2016-09-30 13F WESTERN DIGITAL COM 958102105 287,785 104,504 57.02 16,827 94.26 0.2760
2016-08-08 2016-06-30 13F WESTERN DIGITAL COM 958102105 183,281 111,916 156.82 8,662 156.96 0.1404
2016-05-16 2016-03-31 13F WESTERN DIGITAL COM 958102105 71,365 47,469 198.65 3,371 134.91 0.0561
2016-02-10 2015-12-31 13F WESTERN DIGITAL COM 958102105 23,896 -4,948 -17.15 1,435 -37.36 0.0228
2015-11-16 2015-09-30 13F WESTERN DIGITAL COM 958102105 28,844 -2,877 -9.07 2,291 -7.92 0.0365
2015-08-11 2015-06-30 13F WESTERN DIGITAL COM 958102105 31,721 -8,084 -20.31 2,488 -31.33 0.0341
2015-05-13 2015-03-31 13F WESTERN DIGITAL COM 958102105 39,805 -5,783 -12.69 3,623 -28.21 0.0483
2015-02-05 2014-12-31 13F WESTERN DIGITAL COM 958102105 45,588 3,141 7.40 5,047 22.17 0.0677
2014-11-13 2014-09-30 13F WESTERN DIGITAL COM 958102105 42,447 12,299 40.80 4,131 48.44 0.0570
2014-08-14 2014-06-30 13F WESTERN DIGITAL COM 958102105 30,148 997 3.42 2,783 3.96 0.0386
2014-05-15 2014-03-31 13F WESTERN DIGITAL COM 958102105 29,151 10,669 57.73 2,677 72.60 0.0406
2014-02-03 2013-12-31 13F WESTERN DIGITAL COM 958102105 18,482 14,565 371.84 1,551 525.40 0.0250
2013-11-15 2013-09-30 13F WESTERN DIGITAL COM 958102105 3,917 1,483 60.93 248 64.24 0.0044
2013-08-14 2013-06-30 13F WESTERN DIGITAL COM 958102105 2,434 2,434 151 0.0029
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.