웨스턴 디지털 코퍼레이션
MX ˙ BMV ˙ US9581021055
SecurityMX:WDC / Western Digital Corporation
InstitutionRenaissance Technologies Llc
ManagerJames Simons
Latest Disclosed Ownership1,146,133 shares
Latest Disclosed Value $ 310,017,515
Renaissance Technologies Llc reports 15.48% increase in ownership of WDC / Western Digital Corporation

On May 14, 2026 - Renaissance Technologies Llc filed a 13F-HR form disclosing ownership of 1,146,133 shares of Western Digital Corporation (MX:WDC) valued at $310,017,515 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 992,533 shares of Western Digital Corporation. This represents a change in shares of 15.48% 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)
2026-05-14 2026-03-31 13F WESTERN DIGITAL COM 958102105 1,146,133 153,600 15.48 310,018 81.31 0.4849
2026-02-12 2025-12-31 13F WESTERN DIGITAL COM 958102105 992,533 -156,229 -13.60 170,984 23.97 0.2653
2025-11-13 2025-09-30 13F WESTERN DIGITAL COM 958102105 1,148,762 946,929 469.16 137,920 967.91 0.1821
2025-08-13 2025-06-30 13F WESTERN DIGITAL COM 958102105 201,833 131,900 188.61 12,915 356.84 0.0172
2025-05-14 2025-03-31 13F WESTERN DIGITAL COM 958102105 69,933 -842,200 -92.33 2,827 -94.80 0.0043
2025-02-13 2024-12-31 13F WESTERN DIGITAL COM 958102105 912,133 -306,100 -25.13 54,390 -34.62 0.0805
2024-11-13 2024-09-30 13F WESTERN DIGITAL COM 958102105 1,218,233 1,218,233 83,193 0.1251
2024-08-09 2024-06-30 13F WESTERN DIGITAL COM 958102105 0 -340,133 -100.00 0 -100.00
2024-05-13 2024-03-31 13F WESTERN DIGITAL COM 958102105 340,133 -147,000 -30.18 23 -8.00 0.0365
2024-02-13 2023-12-31 13F WESTERN DIGITAL COM 958102105 487,133 487,133 26 0.0395
2023-08-11 2023-06-30 13F WESTERN DIGITAL COM 958102105 0 -470,833 -100.00 0 -100.00
2023-05-12 2023-03-31 13F WESTERN DIGITAL COM 958102105 470,833 366,351 350.64 18 466.67 0.0235
2023-02-13 2022-12-31 13F WESTERN DIGITAL COM 958102105 104,482 -9,600 -8.41 3 -99.92 0.0045
2022-11-14 2022-09-30 13F WESTERN DIGITAL COM 958102105 114,082 114,082 3,713 0.0053
2022-08-12 2022-06-30 13F WESTERN DIGITAL COM 958102105 0 -1,451,033 -100.00 0 -100.00
2022-05-13 2022-03-31 13F WESTERN DIGITAL COM 958102105 1,451,033 1,185,100 445.64 72,044 315.45 0.0845
2022-02-11 2021-12-31 13F WESTERN DIGITAL COM 958102105 265,933 265,933 17,341 0.0216
2021-05-13 2021-03-31 13F WESTERN DIGITAL COM 958102105 0 -927,933 -100.00 0 -100.00
2021-02-10 2020-12-31 13F WESTERN DIGITAL COM 958102105 927,933 -18,200 -1.92 51,398 48.63 0.0558
2020-11-13 2020-09-30 13F WESTERN DIGITAL COM 958102105 946,133 -325,800 -25.61 34,581 -38.42 0.0345
2020-08-13 2020-06-30 13F WESTERN DIGITAL COM 958102105 1,271,933 1,019,300 403.47 56,156 434.06 0.0485
2020-05-14 2020-03-31 13F WESTERN DIGITAL COM 958102105 252,633 22,800 9.92 10,515 -27.92 0.0102
2020-02-13 2019-12-31 13F WESTERN DIGITAL COM 958102105 229,833 -914,016 -79.91 14,588 -78.62 0.0112
2019-11-13 2019-09-30 13F WESTERN DIGITAL COM 958102105 1,143,849 -1,727,000 -60.16 68,219 -50.03 0.0577
2019-08-12 2019-06-30 13F WESTERN DIGITAL COM 958102105 2,870,849 -12,300 -0.43 136,509 -1.48 0.1202
2019-05-14 2019-03-31 13F WESTERN DIGITAL COM 958102105 2,883,149 1,734,749 151.06 138,564 226.37 0.1260
2019-02-12 2018-12-31 13F WESTERN DIGITAL COM 958102105 1,148,400 239,200 26.31 42,456 -20.23 0.0465
2018-11-13 2018-09-30 13F WESTERN DIGITAL COM 958102105 909,200 -225,649 -19.88 53,225 -39.41 0.0547
2018-08-13 2018-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 1,134,849 -1,246,333 -52.34 87,849 -60.02 0.0958
2018-08-13 2018-06-30 13F WESTERN DIGITAL COM 958102105 2,381,182 219,712
2018-05-14 2018-03-31 13F WESTERN DIGITAL COM 958102105 2,381,182 -50,000 -2.06 219,712 13.63 0.2403
2018-02-13 2017-12-31 13F WESTERN DIGITAL COM 958102105 2,431,182 976,433 67.12 193,352 53.83 0.2132
2017-11-13 2017-09-30 13F WESTERN DIGITAL COM 958102105 1,454,749 1,315,600 945.46 125,690 919.47 0.1479
2017-08-11 2017-06-30 13F WESTERN DIGITAL COM 958102105 139,149 139,149 -90.43 12,329 -90.19 0.0157
2017-02-13 2016-12-31 13F WESTERN DIGITAL COM 958102105 0 -5,019 -100.00 0 -100.00
2016-11-14 2016-09-30 13F WESTERN DIGITAL COM 958102105 5,019 -135,072 -96.42 293 -95.57 0.0005
2016-08-12 2016-06-30 13F WESTERN DIGITAL COM 958102105 140,091 140,091 2,691.21 6,621 2,159.73 0.0126
2016-02-11 2015-12-31 13F WESTERN DIGITAL COM 958102105 0 -169,100 -100.00 0 -100.00
2015-11-12 2015-09-30 13F WESTERN DIGITAL COM 958102105 169,100 -41,400 -19.67 13,433 -18.62 0.0321
2015-08-14 2015-06-30 13F WESTERN DIGITAL COM 958102105 210,500 148,100 237.34 16,507 190.67 0.0376
2015-05-13 2015-03-31 13F WESTERN DIGITAL COM 958102105 62,400 -472,800 -88.34 5,679 -90.41 0.0121
2015-02-13 2014-12-31 13F WESTERN DIGITAL COM 958102105 535,200 -92,400 -14.72 59,247 -3.00 0.1430
2014-11-12 2014-09-30 13F WESTERN DIGITAL COM 958102105 627,600 400,300 176.11 61,078 191.12 0.1672
2014-08-13 2014-06-30 13F WESTERN DIGITAL COM 958102105 227,300 -35,600 -13.54 20,980 -13.09 0.0489
2014-05-14 2014-03-31 13F WESTERN DIGITAL COM 958102105 262,900 -170,202 -39.30 24,139 -33.57 0.0579
2014-02-14 2013-12-31 13F WESTERN DIGITAL COM 958102105 433,102 15,202 3.64 36,337 37.15 0.0870
2013-11-13 2013-09-30 13F WESTERN DIGITAL COM 958102105 417,900 139,300 50.00 26,495 53.17 0.0643
2013-08-12 2013-06-30 13F WESTERN DIGITAL COM 958102105 278,600 278,600 17,298 0.0454
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.