MATTEL INC (MAT) Institutional Buying Activity
Institutional investors tracked by InsiderSet increased exposure to MATTEL INC (MAT) during the quarter ended March 31, 2026 through a combination of new purchases and expanded existing positions disclosed in SEC Form 13F filings.
The largest institutional buyer of MAT during the latest reporting period was Longleaf Partners, which increased its reported MAT position by approximately $61.63M based on quarter-end filing values. Several additional hedge funds and long-term asset managers also reported meaningful increases in MAT exposure during the quarter.
Institutional buying activity can provide insight into investor conviction, sector allocation trends, and smart money positioning toward MATTEL INC (MAT). InsiderSet tracks quarterly accumulation trends, new institutional positions, ownership increases, and estimated performance of newly disclosed holdings using SEC filing data and recent market prices.
The investors highlighted on this page collectively added approximately $133.61M in reported MAT exposure during the latest filing period, reflecting continued institutional interest in MATTEL INC's growth initiatives and strategic positioning.
| Portfolio quarter | Name | Type | Quantity | Remaining | Reported stock balance |
|---|---|---|---|---|---|
| Q1 2026 | Longleaf Partners | Buy | 4,241,829 | 12,812,157 | $186,160,640 |
| Q1 2026 | Ariel Appreciation Fund | Buy | 1,034,950 | 13,567,083 | $197,129,716 |
| Q4 2025 | Longleaf Partners | Buy | 409,032 | 8,570,328 | $170,035,308 |
| Q4 2025 | Sequoia Financial Advisors | Buy | 12,224 | 12,224 | $242,525 |
| Q3 2025 | Longleaf Partners | Buy | 941,031 | 8,161,296 | $137,354,612 |
| Q2 2025 | Longleaf Partners | Buy | 381,331 | 7,220,265 | $142,383,627 |
| Q2 2025 | Ariel Appreciation Fund | Buy | 362,671 | 14,220,786 | $280,433,899 |
| Q4 2024 | Ariel Appreciation Fund | Buy | 12,583 | 14,820,745 | $262,771,809 |
| Q1 2024 | Renaissance Technologies LLC | Buy | 443,400 | 1,049,900 | $20,799 |
| Q1 2024 | Ariel Appreciation Fund | Buy | 112,786 | 15,583,293 | $308,705,035 |
| Q4 2023 | Renaissance Technologies LLC | Buy | 201,500 | 606,500 | $11,451 |
| Q2 2023 | Ariel Appreciation Fund | Buy | 187,157 | 16,466,014 | $321,745,913 |
| Q1 2023 | Ariel Appreciation Fund | Buy | 375,245 | 16,278,857 | $299,693,758 |
| Q1 2023 | Renaissance Technologies LLC | Buy | 110,700 | 1,798,600 | $33,112 |
| Q4 2022 | Renaissance Technologies LLC | Buy | 1,453,200 | 1,687,900 | $30,112 |
| Q4 2022 | Ariel Appreciation Fund | Buy | 141,329 | 15,903,612 | $283,720,438 |
| Q1 2022 | Miller Value Partners | Buy | 22,303 | 4,039,508 | $89,718 |
| Q4 2021 | Miller Value Partners | Buy | 4,017,205 | 4,017,205 | $86,611 |
| Q4 2021 | Longleaf Partners | Buy | 1,878,547 | 20,228,340 | $436,123 |
| Q4 2021 | Ariel Appreciation Fund | Buy | 1,643,083 | 18,276,684 | $394,045 |
| Q4 2021 | Renaissance Technologies LLC | Buy | 629,600 | 1,153,400 | $24,867 |
| Q3 2021 | Ariel Appreciation Fund | Buy | 1,013,421 | 16,633,601 | $308,720 |
| Q2 2021 | Longleaf Partners | Buy | 2,843,544 | 18,990,844 | $381,715 |
| Q2 2021 | Ariel Appreciation Fund | Buy | 310,333 | 15,620,180 | $313,966 |
| Q1 2021 | Renaissance Technologies LLC | Buy | 410,400 | 1,105,900 | $22,030 |
| Q4 2020 | Renaissance Technologies LLC | Buy | 425,600 | 695,500 | $12,136 |
| Q2 2020 | Ariel Appreciation Fund | Buy | 88,498 | 17,687,993 | $171,043 |
| Q1 2020 | Ariel Appreciation Fund | Buy | 2,291,829 | 17,599,495 | $155,052 |
| Q4 2019 | Dodge & Cox Stock Fund | Buy | 79,400 | 38,932,308 | $527,533 |
| Q3 2019 | Ariel Appreciation Fund | Buy | 1,674,949 | 15,371,387 | $175,080 |
Frequently asked questions about MAT activity
Which institutional owners are buying MAT?
Institutional owners buying MAT include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.
What does "buy" mean in MAT activity?
"Buy" means an investor increased their reported position in MAT compared to the prior reporting period. This reflects growing exposure to MATTEL INC (MAT) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).
Is institutional interest in MAT increasing?
Institutional interest in MAT can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.