Martin Marietta Materials, Inc.
MX ˙ BMV ˙ US5732841060
SecurityMX:MLM / Martin Marietta Materials, Inc.
InstitutionClearbridge Investments, LLC
Latest Disclosed Ownership214,672 shares
Latest Disclosed Value $ 126,372,908
Clearbridge Investments, LLC reports 12.07% decrease in ownership of MLM / Martin Marietta Materials, Inc.

On May 13, 2026 - Clearbridge Investments, LLC filed a 13F-HR form disclosing ownership of 214,672 shares of Martin Marietta Materials, Inc. (MX:MLM) valued at $126,372,908 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 244,152 shares of Martin Marietta Materials, Inc.. This represents a change in shares of -12.07% 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)
2026-05-13 2026-03-31 13F Martin Marietta Materials COM 573284106 214,672 -29,480 -12.07 126,373 -16.87 0.0990
2026-02-11 2025-12-31 13F Martin Marietta Materials COM 573284106 244,152 -8,718 -3.45 152,024 -4.61 0.1217
2025-11-13 2025-09-30 13F Martin Marietta Materials COM 573284106 252,870 -7,317 -2.81 159,379 11.58 0.1200
2025-08-12 2025-06-30 13F Martin Marietta Materials COM 573284106 260,187 -3,299 -1.25 142,833 13.38 0.1160
2025-05-13 2025-03-31 13F Martin Marietta Materials COM 573284106 263,486 -21,401 -7.51 125,980 -14.38 0.1101
2025-02-12 2024-12-31 13F Martin Marietta Materials COM 573284106 284,887 4,253 1.52 147,144 -2.59 0.1193
2024-11-12 2024-09-30 13F Martin Marietta Materials COM 573284106 280,634 51,859 22.67 151,051 21.86 0.1188
2024-08-27 2024-06-30 13F/A-1 Martin Marietta Materials COM 573284106 228,775 4,939 2.21 123,950 -9.80 0.1007
2024-08-14 2024-06-30 13F Martin Marietta Materials COM 573284106 228,775 4,939 123,950 0.1014
2024-05-13 2024-03-31 13F Martin Marietta Materials COM 573284106 223,836 -7,384 -3.19 137,422 19.13 0.1089
2024-02-09 2023-12-31 13F Martin Marietta Materials COM 573284106 231,220 -4,865 -2.06 115,358 19.04 0.0992
2023-11-13 2023-09-30 13F Martin Marietta Materials COM 573284106 236,085 -1,475 -0.62 96,908 -11.64 0.0932
2023-08-11 2023-06-30 13F Martin Marietta Materials COM 573284106 237,560 -8,586 -3.49 109,679 25.50 0.0990
2023-05-12 2023-03-31 13F Martin Marietta Materials COM 573284106 246,146 -1,965 -0.79 87,396 4.23 0.0835
2023-02-10 2022-12-31 13F Martin Marietta Materials COM 573284106 248,111 -3,812 -1.51 83,854 3.34 0.0828
2022-11-14 2022-09-30 13F Martin Marietta Materials COM 573284106 251,923 5,245 2.13 81,142 9.92 0.0818
2022-08-11 2022-06-30 13F Martin Marietta Materials COM 573284106 246,678 1,601 0.65 73,816 -21.75 0.0688
2022-05-13 2022-03-31 13F Martin Marietta Materials COM 573284106 245,077 -1,774 -0.72 94,328 -13.26 0.0709
2022-02-11 2021-12-31 13F Martin Marietta Materials COM 573284106 246,851 4,719 1.95 108,743 31.44 0.0741
2021-11-12 2021-09-30 13F Martin Marietta Materials COM 573284106 242,132 11,243 4.87 82,732 1.85 0.0590
2021-08-13 2021-06-30 13F Martin Marietta Materials COM 573284106 230,889 13,142 6.04 81,229 11.08 0.0565
2021-05-13 2021-03-31 13F Martin Marietta Materials COM 573284106 217,747 -4,169 -1.88 73,124 16.04 0.0545
2021-02-10 2020-12-31 13F Martin Marietta Materials COM 573284106 221,916 -7,848 -3.42 63,018 16.53 0.0487
2020-11-12 2020-09-30 13F Martin Marietta Materials COM 573284106 229,764 -2,984 -1.28 54,077 12.48 0.0465
2020-08-14 2020-06-30 13F MARTIN MARIETTA MATLS COM 573284106 232,748 -211,520 -47.61 48,079 -42.81 0.0434
2020-05-22 2020-03-31 13F/A-1 MARTIN MARIETTA MATLS COM 573284106 444,268 -12,138 -2.66 84,069 -33.41 0.0911
2020-05-15 2020-03-31 13F MARTIN MARIETTA MATLS COM 573284106 444,268 -12,138 84,069 91,133.1546
2020-02-14 2019-12-31 13F MARTIN MARIETTA MATLS COM 573284106 456,406 -1,474 -0.32 126,246 0.59 0.1046
2019-11-14 2019-09-30 13F MARTIN MARIETTA MATLS COM 573284106 457,880 7,255 1.61 125,505 21.04 0.1095
2019-08-14 2019-06-30 13F MARTIN MARIETTA MATLS COM 573284106 450,625 5,926 1.33 103,693 15.90 0.0899
2019-05-15 2019-03-31 13F MARTIN MARIETTA MATLS COM 573284106 444,699 -89,678 -16.78 89,464 -2.59 0.0790
2019-02-14 2018-12-31 13F MARTIN MARIETTA MATLS COM 573284106 534,377 5,614 1.06 91,843 -4.54 0.0929
2018-11-28 2018-09-30 13F/A-1 MARTIN MARIETTA MATLS COM 573284106 528,763 -15,841 -2.91 96,208 -20.90 0.0828
2018-11-14 2018-09-30 13F MARTIN MARIETTA MATLS COM 573284106 528,763 -15,841 96,208
2018-08-14 2018-06-30 13F MARTIN MARIETTA MATLS COM 573284106 544,604 9,653 1.80 121,626 9.68 0.0996
2018-05-15 2018-03-31 13F MARTIN MARIETTA MATLS COM 573284106 534,951 -54,490 -9.24 110,895 -14.89 0.1046
2018-02-14 2017-12-31 13F MARTIN MARIETTA MATLS COM 573284106 589,441 25,565 4.53 130,290 12.04 0.1204
2017-11-14 2017-09-30 13F MARTIN MARIETTA MATLS COM 573284106 563,876 39,213 7.47 116,288 -0.42 0.1118
2017-08-14 2017-06-30 13F MARTIN MARIETTA MATLS COM 573284106 524,663 7,056 1.36 116,780 3.37 0.1148
2017-06-07 2017-03-31 13F/A-1 MARTIN MARIETTA MATLS COM 573284106 517,607 4,436 0.86 112,968 -0.63 0.1136
2017-05-15 2017-03-31 13F MARTIN MARIETTA MATLS COM 573284106 517,607 112,968
2017-02-14 2016-12-31 13F MARTIN MARIETTA MATLS COM 573284106 513,171 -13,980 -2.65 113,683 20.40 0.1250
2016-11-14 2016-09-30 13F MARTIN MARIETTA MATLS COM 573284106 527,151 6,647 1.28 94,418 -5.52 0.1063
2016-08-15 2016-06-30 13F MARTIN MARIETTA MATLS COM 573284106 520,504 28,050 5.70 99,937 27.23 0.1181
2016-05-16 2016-03-31 13F MARTIN MARIETTA MATLS COM 573284106 492,454 -20,842 -4.06 78,551 12.05 0.0938
2016-02-16 2015-12-31 13F MARTIN MARIETTA MATLS COM 573284106 513,296 20,255 4.11 70,106 -6.42 0.0812
2015-11-16 2015-09-30 13F MARTIN MARIETTA MATLS COM 573284106 493,041 5,356 1.10 74,918 8.56 0.0897
2015-08-17 2015-06-30 13F/A-1 MARTIN MARIETTA MATLS COM 573284106 487,685 -55,826 -10.27 69,012 -9.17 0.0730
2015-08-14 2015-06-30 13F MARTIN MARIETTA MATLS COM 573284106 509,755 72,135
2015-05-15 2015-03-31 13F MARTIN MARIETTA MATLS COM 573284106 543,511 -4,210 -0.77 75,983 25.75 0.0789
2015-02-17 2014-12-31 13F MARTIN MARIETTA MATLS COM 573284106 547,721 9,585 1.78 60,425 -12.92 0.0636
2014-11-14 2014-09-30 13F MARTIN MARIETTA MATLS COM 573284106 538,136 122,377 29.43 69,387 26.39 0.0764
2014-08-14 2014-06-30 13F MARTIN MARIETTA MATLS COM 573284106 415,759 -31,609 -7.07 54,901 -4.39 0.0617
2014-05-15 2014-03-31 13F MARTIN MARIETTA MATLS COM 573284106 447,368 447,368 57,420 0.0682
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.