Western Digital Corporation
US ˙ NasdaqGS ˙ US9581021055

SecurityWDC / Western Digital Corporation
InstitutionQube Research & Technologies Ltd
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Qube Research & Technologies Ltd ownership in WDC / Western Digital Corporation

On May 15, 2025 - Qube Research & Technologies Ltd filed a 13F-HR form disclosing ownership of 0 shares of Western Digital Corporation (US:WDC) valued at $0 USD as of March 31, 2025. The entity filed a previous 13F-HR on February 14, 2025 disclosing 571,496 shares of Western Digital Corporation. This represents a change in shares of -100.00% during the quarter. The current value of the position is $0 USD.

Qube Research & Technologies Ltd has a history of taking positions in derivatives of the underlying security (WDC) in the form of stock options. The firm currently holds call options representing 63,200 of underlying shares valued at $17,094,968 USD and put options representing 81,500 of underlying shares valued at $22,044,935 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.

WDC / 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)
2025-05-15 2025-03-31 13F WESTERN DIGITAL COM 958102105 0 -571,496 -100.00 0 -100.00
2025-02-14 2024-12-31 13F WESTERN DIGITAL COM 958102105 571,496 -165,835 -22.49 34,078 -32.32 0.0447
2024-11-14 2024-09-30 13F WESTERN DIGITAL COM 958102105 737,331 1,821 0.25 50,352 -9.65 0.0742
2024-08-14 2024-06-30 13F WESTERN DIGITAL COM 958102105 735,510 665,017 943.38 55,730 1,058.61 0.0881
2024-05-14 2024-03-31 13F WESTERN DIGITAL COM 958102105 70,493 -26,113 -27.03 4,810 -4.92 0.0076
2024-02-13 2023-12-31 13F WESTERN DIGITAL COM 958102105 96,606 93,915 3,489.97 5,059 4,046.72 0.0098
2023-11-13 2023-09-30 13F WESTERN DIGITAL COM 958102105 2,691 2,691 123 0.0003
2023-05-15 2023-03-31 13F WESTERN DIGITAL COM 958102105 0 -213,627 -100.00 0 -100.00
2023-02-14 2022-12-31 13F WESTERN DIGITAL COM 958102105 213,627 213,627 6,740 0.0361
2022-11-14 2022-09-30 13F WESTERN DIGITAL COM 958102105 0 -457,300 -100.00 0 -100.00
2022-08-15 2022-06-30 13F WESTERN DIGITAL COM 958102105 457,300 353,672 341.29 20,501 298.46 0.1512
2022-05-09 2022-03-31 13F WESTERN DIGITAL COM 958102105 103,628 103,628 5,145 0.0436
2022-02-10 2021-12-31 13F/A-1 WESTERN DIGITAL COM 958102105 0 -96,348 -100.00 0 -100.00
2022-02-01 2021-12-31 13F WESTERN DIGITAL COM 958102105 0 -96,348 0
2021-11-12 2021-09-30 13F WESTERN DIGITAL COM 958102105 96,348 47,555 97.46 5,438 56.58 0.0682
2021-08-13 2021-06-30 13F WESTERN DIGITAL COM 958102105 48,793 -706 -1.43 3,473 5.12 0.0396
2021-05-14 2021-03-31 13F WESTERN DIGITAL COM 958102105 49,499 19,520 65.11 3,304 98.92 0.0524
2021-02-16 2020-12-31 13F WESTERN DIGITAL COM 958102105 29,979 29,979 1,661 0.0236
2019-08-02 2019-06-30 13F WESTERN DIGITAL COM 958102105 0 -5,355 -100.00 0 -100.00
2019-05-15 2019-03-31 13F WESTERN DIGITAL COM 958102105 5,355 5,355 257 0.0339
2019-02-14 2018-12-31 13F WESTERN DIGITAL COM 958102105 0 -7,520 -100.00 0 -100.00
2018-11-14 2018-09-30 13F WESTERN DIGITAL COM 958102105 7,520 5,273 234.67 440 152.87 0.0585
2018-08-15 2018-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 2,247 1,894 536.54 174 443.75 0.1098
2018-08-14 2018-06-30 13F WESTERN DIGITAL COM 958102105 2,247 1,894 174
2018-05-14 2018-03-31 13F WESTERN DIGITAL COM 958102105 353 353 32 0.0123
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
(%)
2026-05-15 2026-03-31 13F WESTERN DIGITAL COM Call 63,200 -53.50 17,095 -26.98 n/a n/a n/a
2026-02-17 2025-12-31 13F WESTERN DIGITAL COM Call 135,900 -59.78 23,411 -42.29 n/a n/a n/a
2025-11-14 2025-09-30 13F WESTERN DIGITAL COM Call 337,900 -12.55 40,568 64.08 n/a n/a n/a
2025-08-14 2025-06-30 13F WESTERN DIGITAL COM Call 386,400 106.19 24,726 226.36 n/a n/a n/a
2025-05-15 2025-03-31 13F WESTERN DIGITAL COM Call 187,400 189.20 7,577 96.07 n/a n/a n/a
2025-02-14 2024-12-31 13F WESTERN DIGITAL COM Call 64,800 39.06 3,864 21.43 n/a n/a n/a
2024-11-14 2024-09-30 13F WESTERN DIGITAL COM Call 46,600 3,182 n/a n/a n/a
2024-05-14 2024-03-31 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2024-02-13 2023-12-31 13F WESTERN DIGITAL COM Call 2,600 136 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
(%)
2026-05-15 2026-03-31 13F WESTERN DIGITAL COM Put 81,500 -57.99 22,045 -34.04 n/a n/a n/a
2026-02-17 2025-12-31 13F WESTERN DIGITAL COM Put 194,000 -24.86 33,420 7.81 n/a n/a n/a
2025-11-14 2025-09-30 13F WESTERN DIGITAL COM Put 258,200 20.04 30,999 125.22 n/a n/a n/a
2025-08-14 2025-06-30 13F WESTERN DIGITAL COM Put 215,100 221.52 13,764 409.02 n/a n/a n/a
2025-05-15 2025-03-31 13F WESTERN DIGITAL COM Put 66,900 4.69 2,705 -29.03 n/a n/a n/a
2025-02-14 2024-12-31 13F WESTERN DIGITAL COM Put 63,900 118.09 3,810 90.50 n/a n/a n/a
2024-11-14 2024-09-30 13F WESTERN DIGITAL COM Put 29,300 7,225.00 2,001 6,566.67 n/a n/a n/a
2024-08-14 2024-06-30 13F WESTERN DIGITAL COM Put 400 30 n/a n/a n/a
2024-05-14 2024-03-31 13F WESTERN DIGITAL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2024-02-13 2023-12-31 13F WESTERN DIGITAL COM Put 5,900 309 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.