Western Digital Corporation
CH ˙ BRSE ˙ US9581021055
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT
SecurityCH:12355 / Western Digital Corporation
InstitutionPanagora Asset Management Inc
Latest Disclosed Ownership96,741 shares
Latest Disclosed Value $ 26,167,473
Panagora Asset Management Inc reports 151.45% increase in ownership of 12355 / Western Digital Corporation

On May 14, 2026 - Panagora Asset Management Inc filed a 13F-HR form disclosing ownership of 96,741 shares of Western Digital Corporation (CH:12355) valued at $26,167,473 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 38,474 shares of Western Digital Corporation. This represents a change in shares of 151.45% 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.

Upgrade to unlock premium data and export to Excel .

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 96,741 58,267 151.45 26,167 294.85 0.0980
2026-02-13 2025-12-31 13F WESTERN DIGITAL COM 958102105 38,474 38,474 6,628 0.0235
2024-07-29 2024-06-30 13F WESTERN DIGITAL COM 958102105 0 -7,388 -100.00 0 -100.00
2024-05-07 2024-03-31 13F WESTERN DIGITAL COM 958102105 7,388 0 0.00 504 30.57 0.0026
2024-02-08 2023-12-31 13F WESTERN DIGITAL COM 958102105 7,388 -3,518 -32.26 387 -22.33 0.0022
2023-10-31 2023-09-30 13F WESTERN DIGITAL COM 958102105 10,906 3,522 47.70 498 77.50 0.0031
2023-08-11 2023-06-30 13F WESTERN DIGITAL COM 958102105 7,384 0 0.00 280 0.72 0.0016
2023-05-12 2023-03-31 13F WESTERN DIGITAL COM 958102105 7,384 -4,892 -39.85 278 -28.17 0.0018
2023-02-13 2022-12-31 13F WESTERN DIGITAL COM 958102105 12,276 -2,179 -15.07 387 -17.83 0.0025
2022-11-14 2022-09-30 13F WESTERN DIGITAL COM 958102105 14,455 -349,551 -96.03 471 -97.11 0.0033
2022-08-15 2022-06-30 13F WESTERN DIGITAL COM 958102105 364,006 350,196 2,535.81 16,318 2,278.72 0.1070
2022-05-12 2022-03-31 13F WESTERN DIGITAL COM 958102105 13,810 -1,655 -10.70 686 -31.94 0.0037
2022-02-10 2021-12-31 13F WESTERN DIGITAL COM 958102105 15,465 -3,064 -16.54 1,008 -3.63 0.0053
2021-11-10 2021-09-30 13F WESTERN DIGITAL COM 958102105 18,529 -1,180 -5.99 1,046 -25.45 0.0056
2021-08-11 2021-06-30 13F WESTERN DIGITAL COM 958102105 19,709 -1,096 -5.27 1,403 1.01 0.0075
2021-05-12 2021-03-31 13F WESTERN DIGITAL COMMON 958102105 20,805 -5,702 -21.51 1,389 -5.38 0.0078
2021-02-10 2020-12-31 13F WESTERN DIGITAL COMMON 958102105 26,507 2,215 9.12 1,468 65.32 0.0087
2020-11-13 2020-09-30 13F WESTERN DIGITAL COMMON 958102105 24,292 10,467 75.71 888 45.57 0.0056
2020-08-12 2020-06-30 13F WESTERN DIGITAL COMMON 958102105 13,825 1,036 8.10 610 14.66 0.0039
2020-05-14 2020-03-31 13F WESTERN DIGITAL COMMON 958102105 12,789 -7,896 -38.17 532 -59.48 0.0038
2020-02-12 2019-12-31 13F WESTERN DIGITAL COMMON 958102105 20,685 -147,947 -87.73 1,313 -86.94 0.0060
2019-11-12 2019-09-30 13F WESTERN DIGITAL COMMON 958102105 168,632 -98,631 -36.90 10,057 -20.86 0.0464
2019-08-09 2019-06-30 13F WESTERN DIGITAL COMMON 958102105 267,263 -321,773 -54.63 12,708 -55.11 0.0568
2019-05-15 2019-03-31 13F WESTERN DIGITAL COMMON 958102105 589,036 -170,344 -22.43 28,309 0.84 0.1259
2019-02-14 2018-12-31 13F WESTERN DIGITAL COMMON 958102105 759,380 -746,111 -49.56 28,074 -68.15 0.1307
2018-11-13 2018-09-30 13F WESTERN DIGITAL COMMON 958102105 1,505,491 298 0.02 88,131 -24.36 0.3317
2018-08-14 2018-06-30 13F WESTERN DIGITAL COMMON 958102105 1,505,193 61,487 4.26 116,517 -12.53 0.4620
2018-05-15 2018-03-31 13F WESTERN DIGITAL COMMON 958102105 1,443,706 238,255 19.76 133,211 38.95 0.5255
2018-02-14 2017-12-31 13F WESTERN DIGITAL COMMON 958102105 1,205,451 767,193 175.06 95,870 153.19 0.3597
2017-11-14 2017-09-30 13F WESTERN DIGITAL COMMON 958102105 438,258 425,718 3,394.88 37,865 3,308.19 0.1499
2017-08-14 2017-06-30 13F WESTERN DIGITAL COMMON 958102105 12,540 -540 -4.13 1,111 2.97 0.0045
2017-05-15 2017-03-31 13F WESTERN DIGITAL COMMON 958102105 13,080 -11,042 -45.78 1,079 -34.17 0.0045
2017-02-14 2016-12-31 13F WESTERN DIGITAL COMMON 958102105 24,122 -21,418 -47.03 1,639 -38.45 0.0075
2016-11-14 2016-09-30 13F WESTERN DIGITAL COMMON 958102105 45,540 -3,099 -6.37 2,663 15.83 0.0127
2016-08-15 2016-06-30 13F WESTERN DIGITAL COMMON 958102105 48,639 10,032 25.98 2,299 26.04 0.0114
2016-05-16 2016-03-31 13F WESTERN DIGITAL COMMON 958102105 38,607 4,587 13.48 1,824 -10.72 0.0091
2016-02-12 2015-12-31 13F WESTERN DIGITAL COMMON 958102105 34,020 -20,117 -37.16 2,043 -52.50 0.0101
2015-11-13 2015-09-30 13F WESTERN DIGITAL COMMON 958102105 54,137 -46,479 -46.19 4,301 -45.49 0.0227
2015-08-14 2015-06-30 13F WESTERN DIGITAL COMMON 958102105 100,616 -436,054 -81.25 7,890 -83.85 0.0395
2015-05-15 2015-03-31 13F WESTERN DIGITAL COMMON 958102105 536,670 -32,330 -5.68 48,842 -22.46 0.2480
2015-02-13 2014-12-31 13F WESTERN DIGITAL COMMON 958102105 569,000 -16,050 -2.74 62,988 10.63 0.3222
2014-11-12 2014-09-30 13F WESTERN DIGITAL COMMON 958102105 585,050 20,390 3.61 56,937 9.25 0.2759
2014-08-14 2014-06-30 13F WESTERN DIGITAL COMMON 958102105 564,660 300,425 113.70 52,118 114.81 0.2530
2014-05-15 2014-03-31 13F WESTERN DIGITAL COMMON 958102105 264,235 -346,841 -56.76 24,262 -52.68 0.1146
2014-02-21 2013-12-31 13F WESTERN DIGITAL COMMON 958102105 611,076 492,274 414.37 51,269 580.68 0.2374
2013-11-14 2013-09-30 13F WESTERN DIGITAL COMMON 958102105 118,802 1,631 1.39 7,532 3.53 0.0370
2013-08-14 2013-06-30 13F WESTERN DIGITAL COMMON 958102105 117,171 117,171 7,275 0.0372
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.