Seagate Technology Holdings plc
US ˙ NasdaqGS ˙ IE00BKVD2N49

SecuritySTX / Seagate Technology Holdings plc
InstitutionSei Investments Co
Latest Disclosed Ownership299,632 shares
Latest Disclosed Value $ 82,515,668
Sei Investments Co reports 479.62% increase in ownership of STX / Seagate Technology Holdings plc

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 299,632 shares of Seagate Technology Holdings plc (US:STX) valued at $82,515,656 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 51,695 shares of Seagate Technology Holdings plc. This represents a change in shares of 479.62% during the quarter. The current value of the position is $281,860,826 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)
2026-02-13 2025-12-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 299,632 247,937 479.62 82,516 576.19 0.0814
2025-11-13 2025-09-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 51,695 43,152 505.12 12,203 890.50 0.0131
2025-08-14 2025-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 8,543 -498 -5.51 1,233 60.63 0.0014
2025-05-14 2025-03-31 13F/A-1 SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 9,041 3,917 76.44 768 73.53 0.0010
2025-05-13 2025-03-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 5,185 61 441 0.0005
2025-02-11 2024-12-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 5,124 -15,926 -75.66 442 -80.82 0.0006
2024-11-12 2024-09-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 21,050 6,566 45.33 2,306 54.18 0.0030
2024-08-13 2024-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 14,484 3,647 33.65 1,496 48.31 0.0021
2024-05-07 2024-03-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 10,837 -5,840 -35.02 1,008 -29.16 0.0015
2024-02-14 2023-12-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 16,677 -19,259 -53.59 1,424 -39.96 0.0023
2023-11-14 2023-09-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 35,936 -32,108 -47.19 2,370 -43.69 0.0043
2023-08-11 2023-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 68,044 -22,959 -25.23 4,209 -30.05 0.0073
2023-05-12 2023-03-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 91,003 -7,152 -7.29 6,017 16.54 0.0112
2023-02-10 2022-12-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 98,155 26,149 36.32 5,164 34.70 0.0115
2022-11-14 2022-09-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 72,006 -7,215 -9.11 3,833 -33.43 0.0086
2022-08-15 2022-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 79,221 -10,029 -11.24 5,758 -28.55 0.0124
2022-05-13 2022-03-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 89,250 54,038 153.46 8,059 103.66 0.0162
2022-02-14 2021-12-31 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 35,212 -50,106 -58.73 3,957 -43.88 0.0074
2021-11-12 2021-09-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 85,318 5,042 6.28 7,051 0.03 0.0148
2021-08-06 2021-06-30 13F SEAGATE TECHNOLOGY HLDNGS PL ORD SHS G7997R103 80,276 1,009 1.27 7,049 20.43 0.0156
2021-05-12 2021-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 79,267 25,620 47.76 5,853 74.14 0.0147
2021-02-08 2020-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 53,647 34,300 177.29 3,361 238.47 0.0087
2020-12-04 2020-09-30 13F/A-1 SEAGATE TECHNOLOGY SHS G7945M107 19,347 -11,420 -37.12 993 -35.35 0.0029
2020-11-06 2020-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 27,465 -3,302 1,393 3,354.0343
2020-08-17 2020-06-30 13F/A-1 SEAGATE TECHNOLOGY SHS G7945M107 30,767 -3,764 -10.90 1,536 -11.37 0.0048
2020-08-11 2020-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 30,767 -3,764 1,536 4,166.4818
2020-05-14 2020-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 34,531 6,530 23.32 1,733 0.99 0.0064
2020-02-06 2019-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 28,001 6,537 30.46 1,716 40.77 0.0051
2019-11-12 2019-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 21,464 -17,184 -44.46 1,219 -35.54 0.0031
2019-08-14 2019-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 38,648 -2,048 -5.03 1,891 -5.59 0.0062
2019-05-15 2019-03-31 13F SEAGATE TECHNOLOGY S3 G7945M107 40,696 -3,718 -8.37 2,003 1.06 0.0067
2019-02-13 2018-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 44,414 -9,348 -17.39 1,982 -23.47 0.0071
2018-11-08 2018-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 53,762 -27,702 -34.01 2,590 -43.70 0.0094
2018-08-03 2018-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 81,464 25,105 44.54 4,600 39.48 0.0156
2018-05-11 2018-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 56,359 8,059 16.69 3,298 63.27 0.0126
2018-02-08 2017-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 48,300 -65,884 -57.70 2,020 -46.67 0.0070
2017-11-06 2017-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 114,184 18,566 19.42 3,788 2.21 0.0135
2017-07-31 2017-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 95,618 62,792 191.29 3,706 145.92 0.0148
2017-05-05 2017-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 32,826 10,522 47.18 1,507 76.88 0.0066
2017-02-02 2016-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 22,304 18 0.08 852 -0.93 0.0041
2016-11-04 2016-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 22,286 8,744 64.57 860 160.61 0.0044
2016-08-11 2016-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 13,542 -83,060 -85.98 330 -90.08 0.0020
2016-05-10 2016-03-31 13F/A-1 SEAGATE TECHNOLOGY SHS G7945M107 96,602 55,412 134.53 3,328 120.54 0.0207
2016-02-03 2015-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 41,190 -67,674 -62.16 1,509 -69.06 0.0092
2015-11-02 2015-09-30 13F/A-1 SEAGATE TECHNOLOGY SHS G7945M107 108,864 -986 -0.90 4,877 -6.54 0.0448
2015-10-30 2015-09-30 13F SEAGATE TECHNOLOGY SHS G7945M107 108,864 4,878
2015-08-07 2015-06-30 13F/A-1 SEAGATE TECHNOLOGY SHS G7945M107 109,850 -31,805 -22.45 5,218 -29.24 0.0472
2015-08-04 2015-06-30 13F SEAGATE TECHNOLOGY SHS G7945M107 109,850 -31,805 5,218 0.0472
2015-05-14 2015-03-31 13F/A-1 SEAGATE TECHNOLOGY SHS G7945M107 141,655 105,142 287.96 7,374 203.96 0.0640
2015-05-01 2015-03-31 13F SEAGATE TECHNOLOGY SHS G7945M107 141,655 7,374
2015-02-10 2014-12-31 13F SEAGATE TECHNOLOGY SHS G7945M107 36,513 36,513 2,426 0.0214
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.