Western Digital Corporation
MX ˙ BMV ˙ US9581021055
SecurityMX:WDC / Western Digital Corporation
InstitutionHolocene Advisors, LP
Latest Disclosed Ownership761,886 shares
Latest Disclosed Value $ 206,082,544
Holocene Advisors, LP ownership in WDC / Western Digital Corporation

On May 15, 2026 - Holocene Advisors, LP filed a 13F-HR form disclosing ownership of 761,886 shares of Western Digital Corporation (MX:WDC) valued at $206,082,544 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 934,982 shares of Western Digital Corporation. This represents a change in shares of -18.51% during the quarter.

Holocene Advisors, LP 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 0 of underlying shares valued at $0 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.

MX: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)
2026-05-15 2026-03-31 13F WESTERN DIGITAL COM 958102105 761,886 -173,096 -18.51 206,083 27.95 0.4971
2026-02-17 2025-12-31 13F WESTERN DIGITAL COM 958102105 934,982 -1,335,428 -58.82 161,069 -40.91 0.3382
2025-11-14 2025-09-30 13F WESTERN DIGITAL COM 958102105 2,270,410 -3,265,562 -58.99 272,585 -23.05 0.6211
2025-08-14 2025-06-30 13F WESTERN DIGITAL COM 958102105 5,535,972 431,419 8.45 354,247 71.65 0.8645
2025-05-15 2025-03-31 13F WESTERN DIGITAL COM 958102105 5,104,553 2,090,302 69.35 206,377 14.82 0.6021
2025-02-14 2024-12-31 13F WESTERN DIGITAL COM 958102105 3,014,251 -178,511 -5.59 179,740 -17.56 0.5756
2024-11-14 2024-09-30 13F WESTERN DIGITAL COM 958102105 3,192,762 651,847 25.65 218,034 13.25 0.8805
2024-08-14 2024-06-30 13F WESTERN DIGITAL COM 958102105 2,540,915 -862,282 -25.34 192,525 -17.10 0.8037
2024-05-15 2024-03-31 13F WESTERN DIGITAL COM 958102105 3,403,197 167,245 5.17 232,234 37.04 0.8528
2024-02-14 2023-12-31 13F WESTERN DIGITAL COM 958102105 3,235,952 1,804,675 126.09 169,467 159.48 0.6604
2023-11-14 2023-09-30 13F WESTERN DIGITAL COM 958102105 1,431,277 1,411,262 7,051.02 65,309 8,504.61 0.2859
2023-08-14 2023-06-30 13F WESTERN DIGITAL COM 958102105 20,015 -186,151 -90.29 759 -90.23 0.0032
2023-05-15 2023-03-31 13F WESTERN DIGITAL COM 958102105 206,166 -261,030 -55.87 7,766 -47.31 0.0382
2023-02-14 2022-12-31 13F WESTERN DIGITAL COM 958102105 467,196 425,409 1,018.04 14,740 983.82 0.0899
2022-11-14 2022-09-30 13F WESTERN DIGITAL COM 958102105 41,787 28,360 211.22 1,360 125.91 0.0087
2022-08-15 2022-06-30 13F WESTERN DIGITAL COM 958102105 13,427 -319,438 -95.97 602 -96.36 0.0036
2022-05-16 2022-03-31 13F WESTERN DIGITAL COM 958102105 332,865 332,865 16,527 0.0861
2022-02-14 2021-12-31 13F WESTERN DIGITAL COM 958102105 0 -54,368 -100.00 0 -100.00
2021-11-15 2021-09-30 13F WESTERN DIGITAL COM 958102105 54,368 -515,590 -90.46 3,069 -92.43 0.0167
2021-08-16 2021-06-30 13F WESTERN DIGITAL COM 958102105 569,958 569,958 40,564 0.2291
2021-05-17 2021-03-31 13F WESTERN DIGITAL COM 958102105 0 -1,284,497 -100.00 0 -100.00
2021-02-16 2020-12-31 13F WESTERN DIGITAL COM 958102105 1,284,497 1,284,497 71,148 0.4489
2020-11-16 2020-09-30 13F WESTERN DIGITAL COM 958102105 0 -10,247 -100.00 0 -100.00
2020-08-14 2020-06-30 13F WESTERN DIGITAL COM 958102105 10,247 -728,088 -98.61 452 -98.53 0.0040
2020-05-15 2020-03-31 13F WESTERN DIGITAL COM 958102105 738,335 738,335 7,105.38 30,730 6,698.67 0.3300
2020-02-14 2019-12-31 13F WESTERN DIGITAL COM 958102105 0 -339,016 -100.00 0 -100.00
2019-11-14 2019-09-30 13F WESTERN DIGITAL COM 958102105 339,016 106,769 45.97 20,219 83.09 0.2082
2019-08-14 2019-06-30 13F WESTERN DIGITAL COM 958102105 232,247 -4,041 -1.71 11,043 -2.76 0.1408
2019-05-15 2019-03-31 13F WESTERN DIGITAL COM 958102105 236,288 236,288 1.74 11,356 2.83 0.1738
2018-11-14 2018-09-30 13F WESTERN DIGITAL COM 958102105 0 -3,114 -100.00 0 -100.00
2018-08-14 2018-06-30 13F WESTERN DIGITAL COM 958102105 3,114 3,114 241 0.0051
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
(%)
2019-11-14 2019-09-30 13F WESTERN DIGITAL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-08-14 2019-06-30 13F WESTERN DIGITAL COM Call 449,100 21,355 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.