Western Digital Corporation
MX ˙ BMV ˙ US9581021055
SecurityMX:WDC / Western Digital Corporation
InstitutionWestpac Banking Corp
Latest Disclosed Ownership20,720 shares
Latest Disclosed Value $ 5,604,553
Westpac Banking Corp reports 231.10% increase in ownership of WDC / Western Digital Corporation

On May 11, 2026 - Westpac Banking Corp filed a 13F-HR form disclosing ownership of 20,720 shares of Western Digital Corporation (MX:WDC) valued at $5,604,553 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 6,258 shares of Western Digital Corporation. This represents a change in shares of 231.10% 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)
2026-05-11 2026-03-31 13F WESTERN DIGITAL COM 958102105 20,720 14,462 231.10 5,605 419.85 0.1952
2026-02-10 2025-12-31 13F WESTERN DIGITAL CORP USD 0.01 COM 958102105 6,258 126 2.05 1,078 46.47 0.0681
2025-11-14 2025-09-30 13F/A-1 WESTERN DIGITAL CORP USD 0.01 COM 958102105 6,132 6,132 736 0.0456
2025-11-12 2025-09-30 13F WESTERN DIGITAL CORP USD 0.01 COM 958102105 6,132 6,132 736 0.0185
2025-08-11 2025-06-30 13F WESTERN DIGITAL COM 958102105 0 -1,776 -100.00 0 -100.00
2025-05-13 2025-03-31 13F WESTERN DIGITAL COM 958102105 1,776 0 0.00 72 -32.38 0.0053
2025-02-12 2024-12-31 13F WESTERN DIGITAL COM 958102105 1,776 763 75.32 106 52.17 0.0070
2024-11-08 2024-09-30 13F WESTERN DIGITAL COM 958102105 1,013 0 0.00 69 -9.21 0.0046
2024-08-14 2024-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 1,013 -2,270 -69.14 77 -66.07 0.0061
2024-08-13 2024-06-30 13F WESTERN DIGITAL COM 958102105 76 -3,207 77 0.0026
2024-05-09 2024-03-31 13F WESTERN DIGITAL COM 958102105 3,283 142 4.52 224 36.59 0.0171
2024-02-08 2023-12-31 13F WESTERN DIGITAL COM 958102105 3,141 -384 -10.89 164 2.50 0.0136
2023-11-13 2023-09-30 13F WESTERN DIGITAL COM 958102105 3,525 0 0.00 161 20.30 0.0120
2023-08-10 2023-06-30 13F WESTERN DIGITAL COM 958102105 3,525 -28,526 -89.00 134 -88.98 0.0094
2023-05-04 2023-03-31 13F WESTERN DIGITAL COM 958102105 32,051 0 0.00 1,207 19.39 0.0162
2023-02-06 2022-12-31 13F WESTERN DIGITAL COM 958102105 32,051 -2,055 -6.03 1,011 -8.92 0.0149
2022-11-08 2022-09-30 13F WESTERN DIGITAL COM 958102105 34,106 -28,015 -45.10 1,110 -60.13 0.0169
2022-08-10 2022-06-30 13F WESTERN DIGITAL COM 958102105 62,121 4,300 7.44 2,785 -3.00 0.0363
2022-05-11 2022-03-31 13F WESTERN DIGITAL COM 958102105 57,821 34,809 151.26 2,871 91.33 0.0329
2022-02-08 2021-12-31 13F WESTERN DIGITAL COM 958102105 23,012 1,464 6.79 1,501 23.36 0.0155
2021-10-27 2021-09-30 13F WESTERN DIGITAL COM 958102105 21,548 -11,619 -35.03 1,216 -48.47 0.0130
2021-08-11 2021-06-30 13F WESTERN DIGITAL COM 958102105 33,167 0 0.00 2,360 6.64 0.0237
2021-05-13 2021-03-31 13F WESTERN DIGITAL COM 958102105 33,167 12,947 64.03 2,214 97.77 0.0244
2021-02-11 2020-12-31 13F WESTERN DIGITAL COM 958102105 20,220 -59,877 -74.76 1,120 -61.77 0.0127
2020-11-10 2020-09-30 13F WESTERN DIGITAL COM 958102105 80,097 -2,814 -3.39 2,928 -20.03 0.0397
2020-08-12 2020-06-30 13F WESTERN DIGITAL COM 958102105 82,911 -7,102 -7.89 3,661 -2.30 0.0546
2020-05-14 2020-03-31 13F WESTERN DIGITAL COM 958102105 90,013 -64,290 -41.66 3,746 -61.75 0.0646
2020-02-11 2019-12-31 13F WESTERN DIGITAL COM 958102105 154,303 -10,804 -6.54 9,794 -0.54 0.1261
2019-11-13 2019-09-30 13F WESTERN DIGITAL COM 958102105 165,107 -13,897 -7.76 9,847 15.69 0.1369
2019-08-01 2019-06-30 13F WESTERN DIGITAL COM 958102105 179,004 -80,488 -31.02 8,512 -31.75 0.1300
2019-05-14 2019-03-31 13F WESTERN DIGITAL COM 958102105 259,492 88,197 51.49 12,471 96.95 0.2059
2019-02-07 2018-12-31 13F WESTERN DIGITAL COM 958102105 171,295 10,850 6.76 6,333 -32.58 0.1079
2018-11-13 2018-09-30 13F WESTERN DIGITAL COM 958102105 160,445 103,013 179.37 9,392 111.29 0.1610
2018-07-18 2018-06-30 13F WESTERN DIGITAL COM 958102105 57,432 -13,654 -19.21 4,446 -32.23 0.0854
2018-05-01 2018-03-31 13F WESTERN DIGITAL COM 958102105 71,086 20,030 39.23 6,559 61.55 0.1310
2018-01-18 2017-12-31 13F WESTERN DIGITAL COM 958102105 51,056 -6,994 -12.05 4,060 -19.04 0.0923
2017-10-30 2017-09-30 13F WESTERN DIGITAL COM 958102105 58,050 2,466 4.44 5,016 1.85 0.1104
2017-08-09 2017-06-30 13F WESTERN DIGITAL COM 958102105 55,584 0 0.00 4,925 7.35 0.1084
2017-05-18 2017-03-31 13F/A-1 WESTERN DIGITAL COM 958102105 55,584 0 0.00 4,587 13.60 0.0368
2017-05-11 2017-03-31 13F WESTERN DIGITAL COM 958102105 20,816 983
2017-02-09 2016-12-31 13F WESTERN DIGITAL COM 958102105 55,584 7,500 15.60 4,038 43.65 0.0381
2016-11-10 2016-09-30 13F WESTERN DIGITAL COM 958102105 48,084 1,929 4.18 2,811 28.89 0.0304
2016-08-10 2016-06-30 13F WESTERN DIGITAL COM 958102105 46,155 25,339 121.73 2,181 121.87 0.0239
2016-05-13 2016-03-31 13F WESTERN DIGITAL COM 958102105 20,816 -60,071 -74.27 983 -79.76 0.0107
2016-02-11 2015-12-31 13F WESTERN DIGITAL COM 958102105 80,887 -80,242 -49.80 4,857 -62.05 0.0537
2015-11-16 2015-09-30 13F/A-1 WESTERN DIGITAL COM 958102105 161,129 -187,557 -53.79 12,799 -53.19 0.1409
2015-11-12 2015-09-30 13F WESTERN DIGITAL COM 958102105 161,129 12,799
2015-08-12 2015-06-30 13F WESTERN DIGITAL COM 958102105 348,686 56,028 19.14 27,344 -9.21 0.2674
2015-05-12 2015-03-31 13F WESTERN DIGITAL COM 958102105 292,658 -31,656 -9.76 30,116 -16.11 0.2616
2015-02-11 2014-12-31 13F WESTERN DIGITAL COM 958102105 324,314 -34,382 -9.59 35,902 2.84 0.3415
2014-11-12 2014-09-30 13F WESTERN DIGITAL COM 958102105 358,696 -3,678 -1.01 34,908 4.37 0.3402
2014-08-11 2014-06-30 13F WESTERN DIGITAL COM 958102105 362,374 -3,302 -0.90 33,447 -0.38 0.3222
2014-05-12 2014-03-31 13F WESTERN DIGITAL COM 958102105 365,676 -300 -0.08 33,576 9.35 0.3576
2014-02-13 2013-12-31 13F WESTERN DIGITAL COM 958102105 365,976 -41,121 -10.10 30,705 18.98 0.3513
2013-11-12 2013-09-30 13F WESTERN DIGITAL COM 958102105 407,097 -171 -0.04 25,807 16.67 0.3226
2013-08-14 2013-06-30 13F WESTERN DIGITAL COM 958102105 407,268 407,268 22,119 0.3381
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.