Martin Marietta Materials, Inc.
MX ˙ BMV ˙ US5732841060
SecurityMX:MLM / Martin Marietta Materials, Inc.
InstitutionNational Pension Service
Latest Disclosed Ownership89,482 shares
Latest Disclosed Value $ 52,676,264
National Pension Service reports 0.99% increase in ownership of MLM / Martin Marietta Materials, Inc.

On May 12, 2026 - National Pension Service filed a 13F-HR form disclosing ownership of 89,482 shares of Martin Marietta Materials, Inc. (MX:MLM) valued at $52,676,264 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 88,607 shares of Martin Marietta Materials, Inc.. This represents a change in shares of 0.99% 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 MARTIN MARIETTA MATLS COM 573284106 89,482 875 0.99 52,676 -4.52 0.0400
2026-02-10 2025-12-31 13F MARTIN MARIETTA MATLS MARTIN MARIETTA MATLS INC 573284106 88,607 3,787 4.46 55,172 3.20 0.0408
2025-11-04 2025-09-30 13F MARTIN MARIETTA MATLS COM 573284106 84,820 843 1.00 53,460 15.97 0.0415
2025-08-08 2025-06-30 13F MARTIN MARIETTA MATLS COM 573284106 83,977 679 0.82 46,100 15.75 0.0398
2025-05-13 2025-03-31 13F MARTIN MARIETTA MATLS COM 573284106 83,298 13,051 18.58 39,827 9.77 0.0383
2025-02-05 2024-12-31 13F MARTIN MARIETTA MATLS COM 573284106 70,247 -4,268 -5.73 36,283 -9.54 0.0343
2024-10-30 2024-09-30 13F MARTINMARIETTAMATLSINC COM 573284106 74,515 523 0.71 40,108 0.05 0.0387
2024-08-13 2024-06-30 13F MARTIN MARIETTA MATLS COM 573284106 73,992 -1,249 -1.66 40,089 -13.22 0.0461
2024-05-14 2024-03-31 13F MARTIN MARIETTA MATLS COM 573284106 75,241 -1,238 -1.62 46,193 21.06 0.0554
2024-02-07 2023-12-31 13F MARTIN MARIETTA MATLS COM 573284106 76,479 0 0.00 38,156 22.51 0.0531
2023-11-15 2023-09-30 13F MARTIN MARIETTA MATLS COM 573284106 76,479 -2,545 -3.22 31,147 -13.91 0.0498
2023-08-16 2023-06-30 13F MARTIN MARIETTA MATLS COM 573284106 79,024 661 0.84 36,180 31.72 0.0584
2023-05-12 2023-03-31 13F MARTIN MARIETTA MATLS COM 573284106 78,363 0 0.00 27,466 3.71 0.0500
2023-02-24 2022-12-31 13F/A-1 MARTIN MARIETTA MATLS COM 573284106 78,363 -2,431 -3.01 26,484 1.67 0.0521
2023-02-21 2022-12-31 13F MARTIN MARIETTA MATLS COM 573284106 78,363 -2,431 26 0.0521
2023-02-24 2022-09-30 13F/A-1 MARTIN MARIETTA MATLS COM 573284106 80,794 5,834 7.78 26,049 16.13 0.0544
2022-11-18 2022-09-30 13F MARTIN MARIETTA MATLS COM 573284106 80,794 5,834 26,049 0.0544
2022-08-17 2022-06-30 13F MARTIN MARIETTA MATLS COM 573284106 74,960 0 0.00 22,431 -22.25 0.0462
2022-05-13 2022-03-31 13F MARTIN MARIETTA MATLS COM 573284106 74,960 -11,855 -13.66 28,851 -24.56 0.0527
2022-02-15 2021-12-31 13F MARTIN MARIETTA MATLS COM 573284106 86,815 -1,620 -1.83 38,244 26.57 0.0667
2021-11-18 2021-09-30 13F MARTIN MARIETTA MATLS COM 573284106 88,435 -858 -0.96 30,216 -3.81 0.0575
2021-08-17 2021-06-30 13F MARTIN MARIETTA MATLS COM 573284106 89,293 0 0.00 31,414 4.76 0.0597
2021-05-14 2021-03-31 13F MARTIN MARIETTA MATLS COM 573284106 89,293 -3,553 -3.83 29,986 13.73 0.0627
2021-02-19 2020-12-31 13F MARTIN MARIETTA MATLS COM 573284106 92,846 -10,034 -9.75 26,365 10.52 0.0601
2020-11-13 2020-09-30 13F MARTIN MARIETTA MATLS COM 573284106 102,880 0 0.00 23,856 12.25 0.0627
2020-08-11 2020-06-30 13F MARTIN MARIETTA MATLS COM 573284106 102,880 12,359 13.65 21,252 24.07 0.0607
2020-05-27 2020-03-31 13F MARTIN MARIETTA MATLS COM 573284106 90,521 0 0.00 17,129 -32.33 0.0580
2020-02-21 2019-12-31 13F MARTIN MARIETTA MATLS COM 573284106 90,521 -262 -0.29 25,313 1.72 0.0694
2019-11-15 2019-09-30 13F MARTIN MARIETTA MATLS COM 573284106 90,783 4,738 5.51 24,884 25.68 0.0787
2019-08-14 2019-06-30 13F MARTIN MARIETTA MATLS COM 573284106 86,045 5,231 6.47 19,800 21.79 0.0662
2019-05-15 2019-03-31 13F MARTIN MARIETTA MATLS COM 573284106 80,814 3,332 4.30 16,258 11.92 0.0625
2019-02-15 2018-12-31 13F MARTIN MARIETTA MATLS COM 573284106 77,482 3,473 4.69 14,527 7.88 0.0599
2018-11-15 2018-09-30 13F MARTIN MARIETTA MATLS COM 573284106 74,009 0 0.00 13,466 -17.70 0.0548
2018-08-14 2018-06-30 13F MARTIN MARIETTA MATLS COM 573284106 74,009 -3,779 -4.86 16,362 1.47 0.0740
2018-04-13 2018-03-31 13F MARTIN MARIETTA MATLS COM 573284106 77,788 9,905 14.59 16,125 7.46 0.0799
2018-01-17 2017-12-31 13F MARTIN MARIETTA MATLS COM 573284106 67,883 3,873 6.05 15,005 14.35 0.0749
2017-10-16 2017-09-30 13F Martin Marietta Materials COM 573284106 64,010 2,458 3.99 13,122 -3.70 0.0722
2017-07-13 2017-06-30 13F MARTIN MARIETTA MATLS COM 573284106 61,552 5,471 9.76 13,626 14.85 0.0812
2017-04-11 2017-03-31 13F MARTIN MARIETTA MATLS COM 573284106 56,081 3,271 6.19 11,864 1.41 0.0794
2017-01-18 2016-12-31 13F MARTIN MARIETTA MATLS COM 573284106 52,810 3,423 6.93 11,699 32.25 0.0800
2016-10-14 2016-09-30 13F MARTIN MARIETTA MATLS COM 573284106 49,387 4,209 9.32 8,846 1.98 0.0709
2016-08-11 2016-06-30 13F MARTIN MARIETTA MATLS COM 573284106 45,178 4,424 10.86 8,674 33.43 0.0770
2016-05-16 2016-03-31 13F MARTIN MARIETTA MATLS COM 573284106 40,754 1,732 4.44 6,501 21.97 0.0651
2016-02-12 2015-12-31 13F MARTIN MARIETTA MATLS COM 573284106 39,022 2,588 7.10 5,330 -3.72 0.0560
2015-10-15 2015-09-30 13F MARTIN MARIETTA MATLS COM 573284106 36,434 36,434 5,536 0.0700
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.