Ticker · CUSIP 574599106
Holders (tracked)
12
Combined shares
22,626,503
Combined value
$1.42B
Last close
$63.73
Quarter
2025Q4
Tracked holders · last 8 quarters
-3 vs previous quarter over the last 8.
12152024Q12025Q4
Price is +1.8% vs the avg quarter-end implied price across tracked holders.

SEC event timeline

28 events
  1. −84,707 shares · 2025Q4
    13F
  2. −89,440 shares · 2025Q4
    13F
  3. −13,642 shares · 2025Q4
    13F
  4. −1,339,189 shares · 2025Q4
    13F
  5. −2,317 shares · 2025Q4
    13F
  6. +2,085,454 shares · 2025Q4
    13F
  7. +4,090,719 shares · 2025Q4
    13F
  8. +18,569 shares · 2025Q4
    13F
  9. +421,113 shares · 2025Q4
    13F
  10. −37,662 shares · 2025Q4
    13F
  11. +6,776 shares · 2025Q4
    13F
  12. +571,500 shares · 2025Q4
    13F
  13. +3,069,935 shares · 2025Q4
    13F
  14. −4,464 shares · 2025Q4
    13F
  15. +74,971 shares · 2025Q3
    13F
  16. −2,039,026 shares · 2025Q3
    13F
  17. −530,606 shares · 2025Q3
    13F
  18. −8,722 shares · 2025Q3
    13F
  19. −392,413 shares · 2025Q3
    13F
  20. +770 shares · 2025Q3
    13F
  21. +2,741,130 shares · 2025Q3
    13F
  22. +94,647 shares · 2025Q3
    13F
  23. −3,212 shares · 2025Q3
    13F
  24. −174,300 shares · 2025Q3
    13F
  25. −1,910,972 shares · 2025Q3
    13F
  26. +37,662 shares · 2025Q3
    13F
  27. +500,240 shares · 2024Q3
    13F
  28. +4,464 shares · 2025Q3
    13F

Insider activity

No insider transactions in the last 30 days.
Follow-the-investor returns
If you'd copied each holder of MAS…
Cost basis inferred from 13F share-delta history. Sorted by % return on the position they're still holding.
InvestorFirst inCost basisReturnPosition value today
T. Rowe Price2016Q1$29.91+113.1%$19.8M
John Rogers (Ariel Investments)2018Q4$45.19+41.0%$25.8M
Bill Nygren (Harris / Oakmark)2018Q4$52.36+21.7%$733.0M
Renaissance Technologies2016Q1$53.65+18.8%$56.8M
AQR Capital Management2016Q1$59.81+6.5%$50.4M
Izzy Englander (Millennium Mgmt)2016Q1$63.74-0.0%$28.7M
Ken Griffin (Citadel Advisors)2016Q1$63.95-0.4%$1.8M
Ken Griffin (Citadel Advisors)2016Q1$63.95-0.4%$1.8M
Two Sigma Investments2016Q1$66.21-3.7%$2.2M
Wellington Management2016Q1$67.36-5.4%$307.6M
D.E. Shaw & Co.2016Q1$68.43-6.9%$957K
Norges Bank (Norway SWF)2016Q1$243.09-73.8%$195.6M

Who moved on this name in 2025Q4

13F transactions reported for the latest quarter, grouped by direction.
New positions1
Trimmed4

Institutional ownership over time

Distinct super-investors holding this ticker · combined dollar value, by quarter.
QuarterHoldersCombined value
2022Q1
17
$115.57B
2022Q2
14
$116.83B
2022Q3
15
$82.3M
2022Q4
16
$1.37B
2023Q1
14
$1.47B
2023Q2
13
$1.82B
2023Q3
17
$1.65B
2023Q4
16
$2.10B
2024Q1
15
$2.44B
2024Q2
15
$1.88B
2024Q3
15
$939.6M
2024Q4
13
$817.1M
2025Q1
14
$781.9M
2025Q2
14
$1.11B
2025Q3
15
$959.1M
2025Q4
12
$1.42B
Congress members trading this stock
DateMemberTypeAmount rangeFiling
2025-04-07Julie JohnsonSell$1K – $15KPDF ↗

Who owns MAS

12 super-investors · 2025Q4
Tracked stake
22.63M
shares
Combined value
$1.42B
% of shares outstanding
shares-out unknown
Quarter action mix
New1Added7Trim4
#ManagerSharesValue
1Bill Nygren
Harris / Oakmark
11.50M$730M
2Wellington Management4.83M$306M
3Norges Bank
Norway SWF
3.07M$195M
4Renaissance Technologies892.0K$57M
5AQR Capital Management790.8K$50M
6Izzy Englander
Millennium Mgmt
450.0K$29M
7John Rogers
Ariel Investments
405.5K$26M
8Ken Griffin
Citadel Advisors
301.9K$19M
9Two Sigma Investments34.0K$2M
10Ken Griffin
Citadel Advisors
28.9K$2M
11D.E. Shaw & Co.15.0K$953K
12T. Rowe Price310.0K$20K

Recent moves

20 transactions
Embed this chart
Paste this iframe anywhere to embed the live MAS chart.
<iframe src="https://openstocks.me/embed/stock/MAS" width="100%" height="480" frameborder="0" loading="lazy" title="MAS chart by OpenStocks" style="border:0;border-radius:12px;background:transparent"></iframe>