Western Digital Corporation
CH ˙ BRSE ˙ US9581021055
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT
SecurityCH:12355 / Western Digital Corporation
InstitutionNeuberger Berman Group LLC
Latest Disclosed Ownership456,245 shares
Latest Disclosed Value $ 123,409,785
Neuberger Berman Group LLC ownership in 12355 / Western Digital Corporation

On May 14, 2026 - Neuberger Berman Group LLC filed a 13F-HR form disclosing ownership of 456,245 shares of Western Digital Corporation (CH:12355) valued at $123,409,785 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 425,789 shares of Western Digital Corporation. This represents a change in shares of 7.15% during the quarter.

Neuberger Berman Group LLC 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 0 of underlying shares valued at $0 USD and put 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.

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)
2026-05-14 2026-03-31 13F WESTERN DIGITAL Common 958102105 456,245 30,456 7.15 123,410 68.25 0.0939
2026-02-13 2025-12-31 13F WESTERN DIGITAL Common 958102105 425,789 -942,602 -68.88 73,351 -55.09 0.0546
2025-11-12 2025-09-30 13F WESTERN DIGITAL Common 958102105 1,368,391 -85,063 -5.85 163,322 75.60 0.1193
2025-08-25 2025-06-30 13F/A-1 WESTERN DIGITAL Common 958102105 1,453,454 724,900 99.50 93,007 215.76 0.0716
2025-08-13 2025-06-30 13F WESTERN DIGITAL Common 958102105 1,453,454 724,900 93,007 0.0370
2025-05-13 2025-03-31 13F WESTERN DIGITAL Common 958102105 728,554 -822,294 -53.02 29,455 -68.15 0.0247
2025-02-13 2024-12-31 13F WESTERN DIGITAL Common 958102105 1,550,848 -80,554 -4.94 92,477 -16.99 0.0734
2024-11-14 2024-09-30 13F WESTERN DIGITAL Common 958102105 1,631,402 175,610 12.06 111,408 1.00 0.0869
2024-11-14 2024-06-30 13F/A-1 WESTERN DIGITAL Common 958102105 1,455,792 -196,687 -11.90 110,305 -2.18 0.0905
2024-08-13 2024-06-30 13F WESTERN DIGITAL Common 958102105 1,455,792 -196,687 110,305 0.0905
2024-11-14 2024-03-31 13F/A-1 WESTERN DIGITAL Common 958102105 1,652,479 1,405,036 567.82 112,765 770.23 0.0932
2024-05-13 2024-03-31 13F WESTERN DIGITAL Common 958102105 1,652,479 1,405,036 112,765 0.0932
2024-11-14 2023-12-31 13F/A-2 WESTERN DIGITAL Common 958102105 247,443 -3,689 -1.47 12,959 13.08 0.0113
2024-02-09 2023-12-31 13F WESTERN DIGITAL Common 958102105 247,443 -3,689 12,959 0.0113
2023-11-14 2023-09-30 13F WESTERN DIGITAL Common 958102105 251,132 81,500 48.05 11,459 78.10 0.0104
2023-08-11 2023-06-30 13F WESTERN DIGITAL Common 958102105 169,632 93,781 123.64 6,434 125.20 0.0058
2023-05-12 2023-03-31 13F WESTERN DIGITAL Common 958102105 75,851 59,823 373.24 2,857 465.74 0.0026
2023-02-13 2022-12-31 13F WESTERN DIGITAL Common 958102105 16,028 -881,035 -98.21 506 -98.27 0.0005
2022-11-15 2022-09-30 13F WESTERN DIGITAL Common 958102105 897,063 -6,562 -0.73 29,199 -27.92 0.0305
2022-08-15 2022-06-30 13F WESTERN DIGITAL Common 958102105 903,625 -36,840 -3.92 40,509 -13.24 0.0407
2022-05-23 2022-03-31 13F/A-1 WESTERN DIGITAL Common 958102105 940,465 57,350 6.49 46,693 -18.65 0.0396
2022-05-13 2022-03-31 13F WESTERN DIGITAL Common 958102105 940,465 57,350 46,619 0.0208
2022-02-11 2021-12-31 13F WESTERN DIGITAL Common 958102105 883,115 53,102 6.40 57,399 22.71 0.0450
2021-11-12 2021-09-30 13F WESTERN DIGITAL Common 958102105 830,013 214,594 34.87 46,778 7.29 0.0409
2021-08-13 2021-06-30 13F WESTERN DIGITAL Common 958102105 615,419 -84,084 -12.02 43,599 -6.42 0.0381
2021-05-13 2021-03-31 13F WESTERN DIGITAL Common 958102105 699,503 -311,680 -30.82 46,589 -16.76 0.0445
2021-02-10 2020-12-31 13F WESTERN DIGITAL Common 958102105 1,011,183 -25,025 -2.42 55,971 47.81 0.0580
2020-11-12 2020-09-30 13F WESTERN DIGITAL Common 958102105 1,036,208 103,403 11.09 37,866 -8.03 0.0449
2020-08-13 2020-06-30 13F WESTERN DIGITAL Common 958102105 932,805 52,688 5.99 41,170 12.40 0.0512
2020-05-14 2020-03-31 13F WESTERN DIGITAL Common 958102105 880,117 -208,708 -19.17 36,629 -46.99 0.0558
2020-02-12 2019-12-31 13F WESTERN DIGITAL Common 958102105 1,088,825 -53,686 -4.70 69,103 1.41 0.0807
2019-11-13 2019-09-30 13F WESTERN DIGITAL Common 958102105 1,142,511 -187,732 -14.11 68,139 7.72 0.0832
2019-08-13 2019-06-30 13F WESTERN DIGITAL Common 958102105 1,330,243 -56,201 -4.05 63,253 -5.07 0.0757
2019-05-13 2019-03-31 13F WESTERN DIGITAL Common 958102105 1,386,444 -313,705 -18.45 66,632 6.01 0.0817
2019-02-12 2018-12-31 13F WESTERN DIGITAL Common 958102105 1,700,149 -2,375,082 -58.28 62,855 -73.65 0.0876
2018-11-16 2018-09-30 13F/A-1 WESTERN DIGITAL Common 958102105 4,075,231 442,323 12.18 238,564 -15.17 0.2703
2018-11-13 2018-09-30 13F WESTERN DIGITAL Common 958102105 4,075,231 442,323 238,564
2018-08-13 2018-06-30 13F WESTERN DIGITAL Common 958102105 3,632,908 774,095 27.08 281,229 6.61 0.3105
2018-05-08 2018-03-31 13F WESTERN DIGITAL Common 958102105 2,858,813 -21,626 -0.75 263,803 15.16 0.3015
2018-02-14 2017-12-31 13F WESTERN DIGITAL Common 958102105 2,880,439 241,505 9.15 229,082 0.47 0.2633
2017-11-15 2017-09-30 13F WESTERN DIGITAL COMMON STOCK 958102105 2,638,934 19,647 0.75 228,004 -1.75 0.2852
2017-08-08 2017-06-30 13F WESTERN DIGITAL COMMON STOCK 958102105 2,619,287 -438,932 -14.35 232,069 -8.05 0.2980
2017-05-10 2017-03-31 13F WESTERN DIGITAL COMMON STOCK 958102105 3,058,219 -296,769 -8.85 252,395 10.71 0.3257
2017-02-06 2016-12-31 13F WESTERN DIGITAL COMMON STOCK 958102105 3,354,988 -344,305 -9.31 227,971 5.40 0.3062
2016-11-02 2016-09-30 13F WESTERN DIGITAL COMMON STOCK 958102105 3,699,293 305,762 9.01 216,298 34.87 0.2935
2016-08-05 2016-06-30 13F WESTERN DIGITAL COMMON STOCK 958102105 3,393,531 1,722,928 103.13 160,379 103.22 0.2210
2016-05-06 2016-03-31 13F WESTERN DIGITAL COMMON STOCK 958102105 1,670,603 -239,603 -12.54 78,920 -31.20 0.1085
2016-01-28 2015-12-31 13F WESTERN DIGITAL COMMON STOCK 958102105 1,910,206 1,910,206 0.00 114,708 0.1502
2015-07-31 2015-06-30 13F WESTERN DIGITAL COMMON STOCK 958102105 0 -20,335 -100.00 0 -100.00
2015-05-06 2015-03-31 13F WESTERN DIGITAL COMMON STOCK 958102105 20,335 20,335 0.00 1,851 0.0020
2015-02-05 2014-12-31 13F WESTERN DIGITAL COMMON STOCK 958102105 0 -22,358 -100.00 0 -100.00
2014-11-04 2014-09-30 13F WESTERN DIGITAL COMMON STOCK 958102105 22,358 -8,666 -27.93 2,175 -24.06 0.0022
2014-08-05 2014-06-30 13F WESTERN DIGITAL COMMON STOCK 958102105 31,024 114 0.37 2,864 0.92 0.0028
2014-05-05 2014-03-31 13F WESTERN DIGITAL COMMON STOCK 958102105 30,910 5,634 22.29 2,838 33.80 0.0029
2014-02-11 2013-12-31 13F WESTERN DIGITAL COMMON STOCK 958102105 25,276 -149 -0.59 2,121 31.58 0.0022
2013-10-29 2013-09-30 13F/A-1 WESTERN DIGITAL COMMON STOCK 958102105 25,425 25,425 1,612 0.0018
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
(%)
2017-02-06 2016-12-31 13F WESTERN DIGITAL CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2016-11-02 2016-09-30 13F WESTERN DIGITAL CALL Call 126,000 7,367 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
(%)
2017-08-08 2017-06-30 13F WESTERN DIGITAL PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-05-10 2017-03-31 13F WESTERN DIGITAL PUT Put 15,000 1,238 n/a n/a n/a
2017-02-06 2016-12-31 13F WESTERN DIGITAL PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2016-11-02 2016-09-30 13F WESTERN DIGITAL PUT Put 70,000 4,093 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.