Mattel, Inc.
MX ˙ BMV ˙ US5770811025
SecurityMX:MAT / Mattel, Inc.
InstitutionRhumbline Advisers
Latest Disclosed Ownership805,163 shares
Latest Disclosed Value $ 11,698,957
Rhumbline Advisers reports 0.61% decrease in ownership of MAT / Mattel, Inc.

On May 12, 2026 - Rhumbline Advisers filed a 13F-HR form disclosing ownership of 805,163 shares of Mattel, Inc. (MX:MAT) valued at $11,698,957 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 810,122 shares of Mattel, Inc.. This represents a change in shares of -0.61% 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 INC COM COM 577081102 805,163 -4,959 -0.61 11,699 -27.22 0.0100
2026-02-13 2025-12-31 13F MATTEL INC COM COM 577081102 810,122 -59,471 -6.84 16,073 9.82 0.0130
2025-11-06 2025-09-30 13F MATTEL INC COM COM 577081102 869,593 -19,330 -2.17 14,635 -16.51 0.0118
2025-08-12 2025-06-30 13F MATTEL INC COM COM 577081102 888,923 -32,848 -3.56 17,530 -2.12 0.0150
2025-05-29 2025-03-31 13F/A-1 MATTEL INC COM COM 577081102 921,771 -6,421 -0.69 17,910 8.83 0.0168
2025-04-08 2025-03-31 13F MATTEL INC COM COM 577081102 921,771 -6,421 17,910 0.0168
2025-05-29 2024-12-31 13F/A-1 MATTEL INC COM COM 577081102 928,192 17,590 1.93 16,457 -5.13 0.0147
2025-01-30 2024-12-31 13F MATTEL INC COM COM 577081102 928,192 17,590 16,457 0.0147
2024-11-12 2024-09-30 13F MATTEL INC COM COM 577081102 910,602 -24,675 -2.64 17,347 14.07 0.0156
2024-08-01 2024-06-30 13F MATTEL INC COM COM 577081102 935,277 -40,460 -4.15 15,208 -21.33 0.0143
2024-05-09 2024-03-31 13F MATTEL INC COM COM 577081102 975,737 -45,991 -4.50 19,329 0.20 0.0186
2024-02-08 2023-12-31 13F MATTEL INC COM COM 577081102 1,021,728 -53,486 -4.97 19,290 -18.56 0.0202
2023-11-09 2023-09-30 13F MATTEL INC COM COM 577081102 1,075,214 -5,326 -0.49 23,687 12.19 0.0275
2023-08-08 2023-06-30 13F MATTEL INC COM COM 577081102 1,080,540 -7,930 -0.73 21,114 105,465.00 0.0236
2023-05-11 2023-03-31 13F MATTEL INC COM COM 577081102 1,088,470 -9,652 -0.88 20 -99.90 0.0247
2023-02-14 2022-12-31 13F MATTEL INC COM COM 577081102 1,098,122 84,990 8.39 19,590 2.09 0.0263
2022-11-10 2022-09-30 13F MATTEL INC COM COM 577081102 1,013,132 38,154 3.91 19,189 -11.86 0.0286
2022-08-11 2022-06-30 13F MATTEL INC COM COM 577081102 974,978 73,788 8.19 21,771 8.77 0.0318
2022-05-12 2022-03-31 13F MATTEL INC COM COM 577081102 901,190 7,350 0.82 20,015 3.86 0.0258
2022-02-10 2021-12-31 13F MATTEL INC COM COM 577081102 893,840 19,531 2.23 19,271 18.76 0.0236
2021-11-12 2021-09-30 13F MATTEL INC COM COM 577081102 874,309 -7,308 -0.83 16,227 -8.43 0.0220
2021-08-05 2021-06-30 13F MATTEL INC COM COM 577081102 881,617 -25,218 -2.78 17,721 -1.90 0.0233
2021-05-06 2021-03-31 13F MATTEL INC COM COM 577081102 906,835 -13,425 -1.46 18,064 12.49 0.0245
2021-02-10 2020-12-31 13F MATTEL INC COM COM 577081102 920,260 23,926 2.67 16,059 53.13 0.0222
2020-11-12 2020-09-30 13F MATTEL INC COM COM 577081102 896,334 -26,380 -2.86 10,487 17.53 0.0164
2020-08-13 2020-06-30 13F MATTEL INC COM COM 577081102 922,714 38,983 4.41 8,923 14.60 0.0149
2020-05-06 2020-03-31 13F MATTEL INC COM COM 577081102 883,731 18,533 2.14 7,786 -33.58 0.0163
2020-02-05 2019-12-31 13F MATTEL INC COM COM 577081102 865,198 -21,415 -2.42 11,723 16.08 0.0196
2019-10-23 2019-09-30 13F MATTEL INC COM COM 577081102 886,613 -11,348 -1.26 10,099 0.33 0.0185
2019-08-14 2019-06-30 13F MATTEL INC COM COM 577081102 897,961 371,448 70.55 10,066 47.06 0.0189
2019-05-01 2019-03-31 13F MATTEL INC COM COM 577081102 526,513 -54,899 -9.44 6,845 17.85 0.0133
2019-01-31 2018-12-31 13F MATTEL INC COM COM 577081102 581,412 -4,463 -0.76 5,808 -36.86 0.0126
2018-11-07 2018-09-30 13F MATTEL INC COM COM 577081102 585,875 -4,464 -0.76 9,198 -5.11 0.0178
2018-08-06 2018-06-30 13F MATTEL INC COM COM 577081102 590,339 -51,567 -8.03 9,693 14.83 0.0195
2018-05-02 2018-03-31 13F MATTEL INC COM COM 577081102 641,906 1,059 0.17 8,441 -14.36 0.0176
2018-02-09 2017-12-31 13F MATTEL INC COM COM 577081102 640,847 10,537 1.67 9,856 1.01 0.0200
2017-11-06 2017-09-30 13F MATTEL INC COM COM 577081102 630,310 10,352 1.67 9,757 -26.90 0.0212
2017-08-02 2017-06-30 13F MATTEL INC COM COM 577081102 619,958 -56,787 -8.39 13,348 -22.98 0.0305
2017-05-02 2017-03-31 13F MATTEL INC COM COM 577081102 676,745 -7,625 -1.11 17,331 -8.08 0.0405
2017-01-27 2016-12-31 13F MATTEL INC COM COM 577081102 684,370 88,739 14.90 18,854 4.54 0.0478
2016-11-08 2016-09-30 13F MATTEL INC COM COM 577081102 595,631 23,265 4.06 18,036 0.71 0.0497
2016-08-11 2016-06-30 13F MATTEL INC COM COM 577081102 572,366 110,778 24.00 17,909 15.40 0.0531
2016-05-02 2016-03-31 13F MATTEL INC USD1. COM 577081102 461,588 12,127 2.70 15,519 27.08 0.0482
2016-02-03 2015-12-31 13F MATTEL INC USD1. COM 577081102 449,461 -2,937 -0.65 12,212 28.17 0.0393
2015-11-04 2015-09-30 13F MATTEL INC USD1. COM 577081102 452,398 7,640 1.72 9,528 -16.61 0.0324
2015-08-04 2015-06-30 13F MATTEL INC USD1. COM 577081102 444,758 -7,960 -1.76 11,426 10.45 0.0364
2015-05-12 2015-03-31 13F MATTEL INC USD1. COM 577081102 452,718 -1,235 -0.27 10,345 -26.36 0.0298
2015-02-06 2014-12-31 13F MATTEL INC USD1. COM 577081102 453,953 -3,505 -0.77 14,048 0.19 0.0408
2014-11-12 2014-09-30 13F MATTEL INC USD1. COM 577081102 457,458 -12,512 -2.66 14,021 -23.45 0.0421
2014-08-06 2014-06-30 13F MATTEL INC USD1. COM 577081102 469,970 -42,757 -8.34 18,315 -10.94 0.0537
2014-05-06 2014-03-31 13F MATTEL INC USD1. COM 577081102 512,727 -15,152 -2.87 20,565 -18.12 0.0610
2014-02-03 2013-12-31 13F MATTEL INC USD1. COM 577081102 527,879 -38,856 -6.86 25,116 5.87 0.0741
2013-11-05 2013-09-30 13F MATTEL INC USD1. COM 577081102 566,735 1,722 0.30 23,724 -7.33 0.0735
2013-08-07 2013-06-30 13F MATTEL INC USD1. COM 577081102 565,013 565,013 25,601 0.0823
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.