Mattel, Inc.
MX ˙ BMV ˙ US5770811025
SecurityMX:MAT / Mattel, Inc.
InstitutionWinton Capital Group Ltd
Latest Disclosed Ownership509,872 shares
Latest Disclosed Value $ 7,408,440
Winton Capital Group Ltd reports 2,945.28% increase in ownership of MAT / Mattel, Inc.

On May 12, 2026 - Winton Capital Group Ltd filed a 13F-HR form disclosing ownership of 509,872 shares of Mattel, Inc. (MX:MAT) valued at $7,408,440 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 16,743 shares of Mattel, Inc.. This represents a change in shares of 2,945.28% 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.

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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)
2026-05-12 2026-03-31 13F MATTEL COM 577081102 509,872 493,129 2,945.28 7,408 2,131.33 0.2599
2026-02-11 2025-12-31 13F MATTEL COM 577081102 16,743 -30,707 -64.71 332 -58.40 0.0115
2025-11-13 2025-09-30 13F MATTEL COM 577081102 47,450 7,888 19.94 799 2.31 0.0299
2025-08-14 2025-06-30 13F MATTEL COM 577081102 39,562 -8,442 -17.59 780 -16.31 0.0399
2025-05-15 2025-03-31 13F MATTEL COM 577081102 48,004 -966 -1.97 933 7.37 0.0568
2025-02-12 2024-12-31 13F MATTEL COM 577081102 48,970 48,970 868 0.0577
2024-08-09 2024-06-30 13F MATTEL COM 577081102 0 -99,017 -100.00 0 -100.00
2024-05-14 2024-03-31 13F MATTEL COM 577081102 99,017 99,017 1,962 0.1385
2024-02-12 2023-12-31 13F MATTEL COM 577081102 0 -56,075 -100.00 0 -100.00
2023-11-13 2023-09-30 13F MATTEL COM 577081102 56,075 44,894 401.52 1,235 466.51 0.1018
2023-08-14 2023-06-30 13F MATTEL COM 577081102 11,181 -50,720 -81.94 218 -80.86 0.0183
2023-05-12 2023-03-31 13F MATTEL COM 577081102 61,901 -15,179 -19.69 1,140 -17.16 0.0695
2023-02-14 2022-12-31 13F MATTEL COM 577081102 77,080 -37,830 -32.92 1,375 -36.81 0.0906
2022-11-10 2022-09-30 13F MATTEL COM 577081102 114,910 4,703 4.27 2,176 -11.58 0.1420
2022-08-10 2022-06-30 13F MATTEL COM 577081102 110,207 -2,635 -2.34 2,461 -1.80 0.1305
2022-05-11 2022-03-31 13F MATTEL COM 577081102 112,842 -4,364 -3.72 2,506 -0.83 0.1315
2022-02-10 2021-12-31 13F MATTEL COM 577081102 117,206 55,143 88.85 2,527 119.36 0.1531
2021-10-28 2021-09-30 13F MATTEL COM 577081102 62,063 12,677 25.67 1,152 16.01 0.0645
2021-08-10 2021-06-30 13F MATTEL COM 577081102 49,386 25,613 107.74 993 109.49 0.0533
2021-07-21 2021-03-31 13F MATTEL COM 577081102 23,773 1,952 8.95 474 24.41 0.0270
2021-02-12 2020-12-31 13F MATTEL COM 577081102 21,821 -99,583 -82.03 381 -73.17 0.0275
2020-10-30 2020-09-30 13F MATTEL COM 577081102 121,404 25,533 26.63 1,420 53.18 0.0462
2020-08-05 2020-06-30 13F MATTEL COM 577081102 95,871 95,871 927 0.0239
2017-08-17 2017-06-30 13F MATTEL COM 577081102 0 -1,085,746 -100.00 0 -100.00
2017-05-12 2017-03-31 13F MATTEL COM 577081102 1,085,746 809,650 293.25 32,876 332.24 0.5649
2017-02-13 2016-12-31 13F MATTEL COM 577081102 276,096 -809,650 -74.57 7,606 -76.86 0.2511
2016-11-08 2016-09-30 13F MATTEL COM 577081102 1,085,746 69,567 6.85 32,876 3.40 0.5649
2016-08-12 2016-06-30 13F MATTEL COM 577081102 1,016,179 -96,723 -8.69 31,796 -15.02 0.5253
2016-05-06 2016-03-31 13F MATTEL COM 577081102 1,112,902 1,012,950 1,013.44 37,416 1,277.61 0.4056
2016-02-08 2015-12-31 13F MATTEL COM 577081102 99,952 99,952 0.00 2,716 0.0241
2015-11-10 2015-09-30 13F MATTEL COM 577081102 0 -594,284 -100.00 0 -100.00
2015-08-06 2015-06-30 13F MATTEL COM 577081102 594,284 103,355 21.05 15,267 36.09 0.1402
2015-05-12 2015-03-31 13F MATTEL COM 577081102 490,929 -195,172 -28.45 11,218 -47.16 0.0893
2015-03-16 2014-12-31 13F/A-1 MATTEL COM 577081102 686,101 572,215 502.45 21,231 508.16 0.2628
2015-02-13 2014-12-31 13F MATTEL COM 577081102 756,812 23,420
2014-10-28 2014-09-30 13F MATTEL COM 577081102 113,886 -190,539 -62.59 3,491 -70.57 0.0250
2014-08-05 2014-06-30 13F MATTEL COM 577081102 304,425 304,425 11,863 0.0809
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.