Seagate Technology Holdings plc
US ˙ NasdaqGS ˙ IE00BKVD2N49

SecuritySTX / Seagate Technology Holdings plc
InstitutionMackenzie Financial Corp
Latest Disclosed Ownership179,702 shares
Latest Disclosed Value $ 70,400,056
Mackenzie Financial Corp reports 10.04% increase in ownership of STX / Seagate Technology Holdings plc

On May 13, 2026 - Mackenzie Financial Corp filed a 13F-HR form disclosing ownership of 179,702 shares of Seagate Technology Holdings plc (US:STX) valued at $70,400,056 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 18, 2026 disclosing 163,308 shares of Seagate Technology Holdings plc. This represents a change in shares of 10.04% during the quarter. The current value of the position is $166,402,255 USD.

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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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)
2026-05-13 2026-03-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 179,702 16,394 10.04 70,400 54.22 0.0845
2026-02-18 2025-12-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 163,308 -31,368 -16.11 45,649 -0.67 0.0541
2025-11-13 2025-09-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 194,676 27,844 16.69 45,955 90.86 0.0557
2025-08-13 2025-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 166,832 -3,002 -1.77 24,079 66.90 0.0312
2025-05-07 2025-03-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 169,834 150,064 759.05 14,427 745.66 0.0205
2025-05-02 2024-12-31 13F/A-2 SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 19,770 1,877 10.49 1,706 -12.91 0.0023
2025-02-20 2024-12-31 13F/A-1 SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 19,770 1,877 1,706 0.0022
2025-02-14 2024-12-31 13F Seagate Technology Holdings PL Common Stock G7997R103 19,770 1,877 1,681 0.0024
2024-11-13 2024-09-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 17,893 -17,216 -49.04 1,960 -45.96 0.0027
2024-08-14 2024-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 35,109 10,847 44.71 3,626 60.61 0.0054
2024-05-10 2024-03-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 24,262 7,883 48.13 2,258 61.44 0.0033
2024-01-30 2023-12-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 16,379 -1,289 -7.30 1,398 21.04 0.0021
2023-10-25 2023-09-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 17,668 427 2.48 1,156 7.74 0.0019
2023-08-03 2023-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 17,241 -555 -3.12 1,072 -8.84 0.0016
2023-04-24 2023-03-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 17,796 17,796 1,177 0.0018
2023-02-14 2022-12-31 13F Seagate Technology Holdings PL Common Stock G7997R103 0 -15,801 -100.00 0 -100.00
2022-10-07 2022-09-30 13F Seagate Technology Holdings PL Common Stock G7997R103 15,801 -1,612 -9.26 841 -32.40 0.0014
2022-08-10 2022-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 17,413 -783 -4.30 1,244 -23.96 0.0020
2022-05-13 2022-03-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 18,196 -15,628 -46.20 1,636 -57.18 0.0022
2022-02-14 2021-12-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 33,824 1,046 3.19 3,821 41.26 0.0051
2021-11-08 2021-09-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 32,778 -105,854 -76.36 2,705 -77.81 0.0038
2021-08-11 2021-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 138,632 -77,470 -35.85 12,190 -26.50 0.0170
2021-05-14 2021-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 216,102 -139,422 -39.22 16,586 -24.95 0.0253
2021-02-10 2020-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 355,524 -25,260 -6.63 22,099 17.79 0.0477
2020-11-13 2020-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 380,784 222,308 140.28 18,761 144.54 0.0466
2020-08-13 2020-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 158,476 -10,025 -5.95 7,672 -6.70 0.0205
2020-05-14 2020-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 168,501 -55,840 -24.89 8,223 -38.40 0.0264
2020-02-13 2019-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 224,341 111,982 99.66 13,348 120.85 0.0328
2019-11-14 2019-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 112,359 -7,192 -6.02 6,044 7.30 0.0159
2019-08-23 2019-06-30 13F/A-1 SEAGATE TECHNOLOGY SHS G7945M107 119,551 20,208 20.34 5,633 18.39 0.0145
2019-08-14 2019-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 119,551 20,208 5,633
2019-05-15 2019-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 99,343 12,273 14.10 4,758 41.61 0.0115
2019-02-06 2018-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 87,070 -22,644 -20.64 3,360 -35.32 0.0088
2018-11-15 2018-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 109,714 4,446 4.22 5,195 -12.60 0.0126
2018-08-13 2018-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 105,268 544 0.52 5,944 -3.00 0.0152
2018-05-14 2018-03-31 13F/A-1 SEAGATE TECHNOLOGY SHS G7945M107 104,724 -12,637 -10.77 6,128 24.81 0.0156
2018-05-14 2018-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 104,724 6,128
2018-02-13 2017-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 117,361 59,329 102.23 4,910 155.06 0.0119
2017-11-13 2017-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 58,032 -160,773 -73.48 1,925 -77.30 0.0104
2017-08-14 2017-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 218,805 628 0.29 8,479 -15.39 0.0472
2017-05-25 2017-03-31 13F/A-1 SEAGATE TECHNOLOGY SHS G7945M107 218,177 158,009 262.61 10,021 336.26 0.0586
2017-05-12 2017-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 218,177 10,021
2017-02-14 2016-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 60,168 49,576 468.05 2,297 462.99 0.0138
2016-11-15 2016-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 10,592 -20,946 -66.42 408 -46.87 0.0025
2016-08-12 2016-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 31,538 14,055 80.39 768 27.57 0.0043
2016-05-12 2016-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 17,483 3,170 22.15 602 14.67 0.0055
2016-02-12 2015-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 14,313 -10,494 -42.30 525 -52.75 0.0033
2015-11-13 2015-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 24,807 2,324 10.34 1,111 4.03 0.0067
2015-08-13 2015-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 22,483 1,588 7.60 1,068 -1.75 0.0058
2015-05-13 2015-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 20,895 2,074 11.02 1,087 -13.18 0.0057
2015-02-11 2014-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 18,821 2,812 17.57 1,252 36.53 0.0064
2014-11-12 2014-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 16,009 10,161 173.75 917 176.20 0.0046
2014-08-11 2014-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 5,848 999 20.60 332 22.06 0.0015
2014-05-14 2014-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 4,849 4,849 272 0.0013
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.