Western Digital Corporation
CH ˙ BRSE ˙ US9581021055
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT
SecurityCH:12355 / Western Digital Corporation
InstitutionHsbc Holdings Plc
Latest Disclosed Ownership1,545,167 shares
Latest Disclosed Value $ 416,999,595
Hsbc Holdings Plc ownership in 12355 / Western Digital Corporation

On April 30, 2026 - Hsbc Holdings Plc filed a 13F-HR form disclosing ownership of 1,545,167 shares of Western Digital Corporation (CH:12355) valued at $416,999,595 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on March 20, 2026 disclosing 1,267,785 shares of Western Digital Corporation. This represents a change in shares of 21.88% during the quarter.

Hsbc Holdings Plc has a history of taking positions in derivatives of the underlying security (12355) in the form of stock options. The firm currently holds call options representing 1,000 of underlying shares valued at $270,490 USD and put options representing 150,100 of underlying shares valued at $40,451,950 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

CH:12355 / Western Digital Corporation Historical Put/Call Ratio
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)
2026-04-30 2026-03-31 13F WESTERN DIGITAL COM 958102105 1,545,167 277,382 21.88 417,000 91.20 0.2177
2026-03-20 2025-12-31 13F/A-1 WESTERN DIGITAL COM 958102105 1,267,785 -611,777 -32.55 218,093 -2.07 0.1112
2026-03-06 2025-12-31 13F WESTERN DIGITAL COM 958102105 1,267,785 -611,777 218,093 0.0100
2025-11-13 2025-09-30 13F WESTERN DIGITAL COM 958102105 1,879,562 732,088 63.80 222,710 202.70 0.1229
2025-08-13 2025-06-30 13F WESTERN DIGITAL COM 958102105 1,147,474 -842,245 -42.33 73,574 -7.20 0.0442
2025-05-14 2025-03-31 13F WESTERN DIGITAL COM 958102105 1,989,719 371,556 22.96 79,287 -17.97 0.0490
2025-02-14 2024-12-31 13F WESTERN DIGITAL COM 958102105 1,618,163 407,228 33.63 96,653 16.52 0.0562
2024-11-14 2024-09-30 13F WESTERN DIGITAL COM 958102105 1,210,935 -236,768 -16.35 82,949 -25.01 0.0483
2024-08-12 2024-06-30 13F WESTERN DIGITAL COM 958102105 1,447,703 -95,106 -6.16 110,619 5.09 0.0676
2024-05-15 2024-03-31 13F WESTERN DIGITAL COM 958102105 1,542,809 324,876 26.67 105,266 64.49 0.0713
2024-02-12 2023-12-31 13F WESTERN DIGITAL COM 958102105 1,217,933 617,126 102.72 63,994 133.41 0.0558
2023-11-13 2023-09-30 13F WESTERN DIGITAL COM 958102105 600,807 -182,451 -23.29 27,418 -7.74 0.0285
2023-08-11 2023-06-30 13F WESTERN DIGITAL COM 958102105 783,258 135,131 20.85 29,719 21.59 0.0303
2023-05-15 2023-03-31 13F WESTERN DIGITAL COM 958102105 648,127 -1,206,084 -65.05 24,441 -57.98 0.0293
2023-02-14 2022-12-31 13F WESTERN DIGITAL COM 958102105 1,854,211 502,231 37.15 58,165 30.60 0.0669
2022-11-14 2022-09-30 13F WESTERN DIGITAL COM 958102105 1,351,980 361 0.03 44,538 -27.14 0.0726
2022-08-11 2022-06-30 13F WESTERN DIGITAL COM 958102105 1,351,619 689,535 104.15 61,129 84.91 0.0854
2022-05-16 2022-03-31 13F WESTERN DIGITAL COM 958102105 662,084 358,558 118.13 33,059 66.68 0.0402
2022-02-11 2021-12-31 13F WESTERN DIGITAL COM 958102105 303,526 -44,668 -12.83 19,834 0.59 0.0183
2021-11-12 2021-09-30 13F WESTERN DIGITAL COM 958102105 348,194 -2,471 -0.70 19,718 -20.73 0.0199
2021-08-13 2021-06-30 13F WESTERN DIGITAL COM 958102105 350,665 60,396 20.81 24,874 29.51 0.0265
2021-05-14 2021-03-31 13F WESTERN DIGITAL COM 958102105 290,269 -248,360 -46.11 19,206 -33.64 0.0226
2021-02-25 2020-12-31 13F/A-1 WESTERN DIGITAL COM 958102105 538,629 80,967 17.69 28,940 71.34 0.0386
2021-02-12 2020-12-31 13F WESTERN DIGITAL COM 958102105 538,629 80,967 28,940 6,871.4197
2020-11-12 2020-09-30 13F WESTERN DIGITAL COM 958102105 457,662 97,158 26.95 16,890 6.12 0.0269
2020-08-14 2020-06-30 13F WESTERN DIGITAL COM 958102105 360,504 -89,428 -19.88 15,916 -16.28 0.0302
2020-05-15 2020-03-31 13F WESTERN DIGITAL COM 958102105 449,932 74,033 19.69 19,012 -20.18 0.0442
2020-02-14 2019-12-31 13F WESTERN DIGITAL COM 958102105 375,899 49,793 15.27 23,820 22.47 0.0414
2019-11-14 2019-09-30 13F WESTERN DIGITAL COM 958102105 326,106 -105,537 -24.45 19,449 -5.24 0.0363
2019-08-13 2019-06-30 13F WESTERN DIGITAL COM 958102105 431,643 -16,878 -3.76 20,524 -4.78 0.0390
2019-05-15 2019-03-31 13F WESTERN DIGITAL COM 958102105 448,521 -172,323 -27.76 21,555 -6.07 0.0393
2019-02-13 2018-12-31 13F WESTERN DIGITAL COM 958102105 620,844 70,685 12.85 22,948 -28.74 0.0424
2018-11-13 2018-09-30 13F WESTERN DIGITAL COM 958102105 550,159 95,761 21.07 32,205 -8.44 0.0518
2018-08-10 2018-06-30 13F WESTERN DIGITAL COM 958102105 454,398 -387,482 -46.03 35,173 -54.66 0.0626
2018-05-11 2018-03-31 13F WESTERN DIGITAL COM 958102105 841,880 -129,504 -13.33 77,581 0.42 0.1155
2018-02-14 2017-12-31 13F WESTERN DIGITAL COM 958102105 971,384 234,230 31.77 77,254 21.30 0.1118
2017-11-14 2017-09-30 13F WESTERN DIGITAL COM 958102105 737,154 57,306 8.43 63,690 5.74 0.1020
2017-08-14 2017-06-30 13F WESTERN DIGITAL COM 958102105 679,848 383,983 129.78 60,235 145.78 0.1108
2017-05-15 2017-03-31 13F WESTERN DIGITAL COM 958102105 295,865 31,115 11.75 24,508 36.24 0.0512
2017-02-09 2016-12-31 13F WESTERN DIGITAL COM 958102105 264,750 -267,316 -50.24 17,989 -42.18 0.0420
2016-11-14 2016-09-30 13F WESTERN DIGITAL COM 958102105 532,066 -6,748 -1.25 31,112 22.32 0.0774
2016-08-12 2016-06-30 13F WESTERN DIGITAL COM 958102105 538,814 -28,828 -5.08 25,434 -4.97 0.0700
2016-05-13 2016-03-31 13F WESTERN DIGITAL COM 958102105 567,642 33,816 6.33 26,763 -16.70 0.0754
2016-02-12 2015-12-31 13F WESTERN DIGITAL COM 958102105 533,826 -11,439 -2.10 32,130 -25.83 0.0774
2015-11-12 2015-09-30 13F WESTERN DIGITAL COM 958102105 545,265 -19,713 -3.49 43,318 -2.64 0.1092
2015-08-13 2015-06-30 13F WESTERN DIGITAL COM 958102105 564,978 111,075 24.47 44,493 7.58 0.0908
2015-05-14 2015-03-31 13F WESTERN DIGITAL COM 958102105 453,903 -37,264 -7.59 41,358 -24.09 0.0794
2015-02-13 2014-12-31 13F WESTERN DIGITAL COM 958102105 491,167 18,714 3.96 54,482 18.57 0.1130
2014-11-18 2014-09-30 13F WESTERN DIGITAL COM 958102105 472,453 35,837 8.21 45,951 13.99 0.0962
2014-08-14 2014-06-30 13F WESTERN DIGITAL COM 958102105 436,616 -128,649 -22.76 40,310 -22.24 0.0872
2014-05-14 2014-03-31 13F WESTERN DIGITAL COM 958102105 565,265 354,948 168.77 51,842 194.06 0.1239
2014-02-14 2013-12-31 13F WESTERN DIGITAL COM 958102105 210,317 -35,749 -14.53 17,630 13.04 0.0459
2013-11-14 2013-09-30 13F WESTERN DIGITAL COM 958102105 246,066 -41,859 -14.54 15,596 -12.99 0.0426
2013-10-10 2013-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 287,925 -47,477 -14.16 17,924 6.28 0.0543
2013-08-14 2013-06-30 13F WESTERN DIGITAL COM 958102105 287,925 17,924
2013-10-10 2013-03-31 13F/A-1 WESTERN DIGITAL COM 958102105 335,402 -1,664 -0.49 16,865 17.75 0.0614
2013-05-22 2013-03-31 13F WESTERN DIGITAL COM 958102105 336,120 16,901
2013-06-17 2012-12-31 13F/A-1 WESTERN DIGITAL COM 958102105 337,784 66,064 14,354 0.0553
2013-10-10 2012-12-31 13F/A-2 WESTERN DIGITAL COM 958102105 337,066 65,346 24.05 14,323 36.11 0.0556
2013-06-21 2012-09-30 13F/A-1 WESTERN DIGITAL COM 958102105 272,698 23,449 10,561 0.0414
2013-10-11 2012-09-30 13F/A-2 WESTERN DIGITAL COM 958102105 271,720 22,471 9.02 10,523 37.47 0.0416
2013-10-11 2012-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 249,249 5,394 2.21 7,655 -24.16 0.0347
2013-10-11 2012-03-31 13F/A-1 WESTERN DIGITAL COM 958102105 243,855 243,855 10,093 0.0443
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-04-30 2026-03-31 13F WESTERN DIGITAL COM Call 1,000 0.00 270 56.98 n/a n/a n/a
2026-03-20 2025-12-31 13F/A WESTERN DIGITAL COM Call 1,000 172 n/a n/a n/a
2025-11-13 2025-09-30 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-08-13 2025-06-30 13F WESTERN DIGITAL COM Call 165,000 10,597 n/a n/a n/a
2025-05-14 2025-03-31 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-14 2024-12-31 13F WESTERN DIGITAL COM Call 700 75.00 42 51.85 n/a n/a n/a
2024-11-14 2024-09-30 13F WESTERN DIGITAL COM Call 400 27 n/a n/a n/a
2024-08-12 2024-06-30 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2024-05-15 2024-03-31 13F WESTERN DIGITAL COM Call 22,900 -75.27 1,563 -67.94 n/a n/a n/a
2024-02-12 2023-12-31 13F WESTERN DIGITAL COM Call 92,600 14.18 4,873 31.60 n/a n/a n/a
2023-11-13 2023-09-30 13F WESTERN DIGITAL COM Call 81,100 16.19 3,702 39.70 n/a n/a n/a
2023-08-11 2023-06-30 13F WESTERN DIGITAL COM Call 69,800 -0.29 2,651 0.15 n/a n/a n/a
2023-05-15 2023-03-31 13F WESTERN DIGITAL COM Call 70,000 -6.29 2,646 13.27 n/a n/a n/a
2023-02-14 2022-12-31 13F WESTERN DIGITAL COM Call 74,700 1.22 2,337 -4.61 n/a n/a n/a
2022-11-14 2022-09-30 13F WESTERN DIGITAL COM Call 73,800 0.00 2,449 -26.83 n/a n/a n/a
2022-08-11 2022-06-30 13F WESTERN DIGITAL COM Call 73,800 3,347 n/a n/a n/a
2021-11-12 2021-09-30 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-08-13 2021-06-30 13F WESTERN DIGITAL COM Call 2,900 206 n/a n/a n/a
2021-02-25 2020-12-31 13F/A WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-11-12 2020-09-30 13F WESTERN DIGITAL COM Call 7,700 285 n/a n/a n/a
2020-08-14 2020-06-30 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-05-15 2020-03-31 13F WESTERN DIGITAL COM Call 200 0.00 8 -33.33 n/a n/a n/a
2020-02-14 2019-12-31 13F WESTERN DIGITAL COM Call 200 0.00 12 50.00 n/a n/a n/a
2019-08-13 2019-06-30 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-05-15 2019-03-31 13F WESTERN DIGITAL COM Call 25,000 1,202 n/a n/a n/a
2019-02-13 2018-12-31 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-11-13 2018-09-30 13F WESTERN DIGITAL COM Call 6,200 0.00 363 -24.37 n/a n/a n/a
2018-08-10 2018-06-30 13F WESTERN DIGITAL COM Call 6,200 -91.38 480 -92.76 n/a n/a n/a
2018-05-11 2018-03-31 13F WESTERN DIGITAL COM Call 71,900 1,059.68 6,634 1,282.08 n/a n/a n/a
2017-08-14 2017-06-30 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-05-15 2017-03-31 13F WESTERN DIGITAL COM Call 500 42 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-04-30 2026-03-31 13F WESTERN DIGITAL COM Put 150,100 0.00 40,452 56.82 n/a n/a n/a
2026-03-20 2025-12-31 13F/A WESTERN DIGITAL COM Put 150,100 25,795 n/a n/a n/a
2025-11-13 2025-09-30 13F WESTERN DIGITAL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-08-13 2025-06-30 13F WESTERN DIGITAL COM Put 17,100 1,098 n/a n/a n/a
2025-05-14 2025-03-31 13F WESTERN DIGITAL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-14 2024-12-31 13F WESTERN DIGITAL COM Put 11,500 687 n/a n/a n/a
2024-05-15 2024-03-31 13F WESTERN DIGITAL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2024-02-12 2023-12-31 13F WESTERN DIGITAL COM Put 128,600 6,767 n/a n/a n/a
2023-08-11 2023-06-30 13F WESTERN DIGITAL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-05-15 2023-03-31 13F WESTERN DIGITAL COM Put 36,500 1,380 n/a n/a n/a
2020-02-14 2019-12-31 13F WESTERN DIGITAL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-11-14 2019-09-30 13F WESTERN DIGITAL COM Put 50,000 -38.35 2,982 -22.69 n/a n/a n/a
2019-08-13 2019-06-30 13F WESTERN DIGITAL COM Put 81,100 189.64 3,857 186.55 n/a n/a n/a
2019-05-15 2019-03-31 13F WESTERN DIGITAL COM Put 28,000 -25.33 1,346 -2.89 n/a n/a n/a
2019-02-13 2018-12-31 13F WESTERN DIGITAL COM Put 37,500 165.96 1,386 67.80 n/a n/a n/a
2018-11-13 2018-09-30 13F WESTERN DIGITAL COM Put 14,100 235.71 826 154.15 n/a n/a n/a
2018-08-10 2018-06-30 13F WESTERN DIGITAL COM Put 4,200 -91.04 325 -92.49 n/a n/a n/a
2018-05-11 2018-03-31 13F WESTERN DIGITAL COM Put 46,900 46,800.00 4,327 53,987.50 n/a n/a n/a
2018-02-14 2017-12-31 13F WESTERN DIGITAL COM Put 100 0.00 8 -11.11 n/a n/a n/a
2017-11-14 2017-09-30 13F WESTERN DIGITAL COM Put 100 0.00 9 0.00 n/a n/a n/a
2017-08-14 2017-06-30 13F WESTERN DIGITAL COM Put 100 0.00 9 0.00 n/a n/a n/a
2016-08-12 2016-06-30 13F WESTERN DIGITAL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2016-05-13 2016-03-31 13F WESTERN DIGITAL COM Put 3,100 146 n/a n/a n/a
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.