馬丁瑪麗埃塔材料公司
US ˙ NYSE ˙ US5732841060

SecurityMLM / Martin Marietta Materials, Inc.
InstitutionAsset Management One Co., Ltd.
Latest Disclosed Ownership24,889 shares
Latest Disclosed Value $ 14,651,657
Asset Management One Co., Ltd. reports 19.08% decrease in ownership of MLM / Martin Marietta Materials, Inc.

On May 8, 2026 - Asset Management One Co., Ltd. filed a 13F-HR form disclosing ownership of 24,889 shares of Martin Marietta Materials, Inc. (US:MLM) valued at $14,651,657 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 27, 2026 disclosing 30,759 shares of Martin Marietta Materials, Inc.. This represents a change in shares of -19.08% during the quarter. The current value of the position is $14,457,025 USD.

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)
2026-05-08 2026-03-31 13F MARTIN MARIETTA MATLS COM 573284106 24,889 -5,870 -19.08 14,652 -25.25 0.0432
2026-01-27 2025-12-31 13F MARTIN MARIETTA MATLS COM 573284106 30,759 -1,474 -4.57 19,600 -3.52 0.0545
2025-10-22 2025-09-30 13F MARTIN MARIETTA MATLS COM 573284106 32,233 237 0.74 20,316 15.66 0.0589
2025-07-31 2025-06-30 13F MARTIN MARIETTA MATLS COM 573284106 31,996 1,099 3.56 17,565 18.90 0.0551
2025-04-23 2025-03-31 13F MARTIN MARIETTA MATLS COM 573284106 30,897 -245 -0.79 14,773 -10.30 0.0511
2025-01-30 2024-12-31 13F MARTIN MARIETTA MATLS COM 573284106 31,142 8,367 36.74 16,469 34.35 0.0566
2024-10-30 2024-09-30 13F MARTIN MARIETTA MATLS COM 573284106 22,775 222 0.98 12,259 0.32 0.0436
2024-07-18 2024-06-30 13F MARTIN MARIETTA MATLS COM 573284106 22,553 -457 -1.99 12,219 -13.50 0.0467
2024-05-02 2024-03-31 13F MARTIN MARIETTA MATLS COM 573284106 23,010 -1,491 -6.09 14,127 15.72 0.0544
2024-01-24 2023-12-31 13F MARTIN MARIETTA MATLS COM 573284106 24,501 380 1.58 12,207 23.29 0.0491
2023-10-19 2023-09-30 13F MARTIN MARIETTA MATLS COM 573284106 24,121 -37 -0.15 9,901 -11.23 0.0441
2023-07-31 2023-06-30 13F MARTIN MARIETTA MATLS COM 573284106 24,158 -157 -0.65 11,154 29.19 0.0472
2023-04-25 2023-03-31 13F MARTIN MARIETTA MATLS COM 573284106 24,315 364 1.52 8,633 5.85 0.0391
2023-02-06 2022-12-31 13F MARTIN MARIETTA MATLS COM 573284106 23,951 -1,135 -4.52 8,157 0.95 0.0398
2022-11-04 2022-09-30 13F MARTIN MARIETTA MATLS COM 573284106 25,086 -168 -0.67 8,079 6.91 0.0411
2022-07-29 2022-06-30 13F MARTIN MARIETTA MATLS COM 573284106 25,254 -460 -1.79 7,557 -23.64 0.0355
2022-05-13 2022-03-31 13F MARTIN MARIETTA MATLS COM 573284106 25,714 -924 -3.47 9,897 -15.88 0.0386
2022-02-09 2021-12-31 13F MARTIN MARIETTA MATLS COM 573284106 26,638 20 0.08 11,765 29.37 0.0410
2021-11-02 2021-09-30 13F MARTIN MARIETTA MATLS COM 573284106 26,618 -1,240 -4.45 9,094 -7.20 0.0349
2021-08-03 2021-06-30 13F MARTIN MARIETTA MATLS COM 573284106 27,858 -760 -2.66 9,800 1.98 0.0365
2021-05-14 2021-03-31 13F MARTIN MARIETTA MATLS COM 573284106 28,618 -923 -3.12 9,610 18.55 0.0382
2021-02-12 2020-12-31 13F MARTIN MARIETTA MATLS COM 573284106 29,541 -618 -2.05 8,106 14.20 0.0334
2020-11-13 2020-09-30 13F MARTIN MARIETTA MATLS COM 573284106 30,159 -862 -2.78 7,098 10.77 0.0326
2020-08-14 2020-06-30 13F MARTIN MARIETTA MATLS COM 573284106 31,021 321 1.05 6,408 10.31 0.0315
2020-05-14 2020-03-31 13F MARTIN MARIETTA MATLS COM 573284106 30,700 -750 -2.38 5,809 -33.95 0.0339
2020-02-14 2019-12-31 13F MARTIN MARIETTA MATLS COM 573284106 31,450 -7 -0.02 8,795 2.01 0.0396
2019-11-14 2019-09-30 13F MARTIN MARIETTA MATLS COM 573284106 31,457 -349 -1.10 8,622 17.79 0.0415
2019-08-14 2019-06-30 13F MARTIN MARIETTA MATLS COM 573284106 31,806 2,841 9.81 7,320 25.67 0.0360
2019-05-15 2019-03-31 13F MARTIN MARIETTA MATLS COM 573284106 28,965 -69,096 -70.46 5,825 -65.42 0.0315
2019-02-13 2018-12-31 13F MARTIN MARIETTA MATLS COM 573284106 98,061 784 0.81 16,845 -4.96 0.0402
2018-11-14 2018-09-30 13F MARTIN MARIETTA MATLS COM 573284106 97,277 448 0.46 17,725 -17.99 0.0364
2018-08-14 2018-06-30 13F MARTIN MARIETTA MATLS COM 573284106 96,829 -483 -0.50 21,613 7.14 0.0472
2018-05-14 2018-03-31 13F MARTIN MARIETTA MATLS COM 573284106 97,312 -3,391 -3.37 20,173 -9.26 0.0454
2018-02-14 2017-12-31 13F MARTIN MARIETTA MATLS COM 573284106 100,703 -16,164 -13.83 22,232 -7.65 0.0490
2017-11-14 2017-09-30 13F MARTIN MARIETTA MATLS COM 573284106 116,867 -28,315 -19.50 24,073 -25.36 0.0565
2017-08-14 2017-06-30 13F MARTIN MARIETTA MATLS COM 573284106 145,182 12,419 9.35 32,251 12.46 0.0823
2017-05-11 2017-03-31 13F MARTIN MARIETTA MATLS COM 573284106 132,763 28,575 27.43 28,678 24.08 0.0753
2017-05-02 2016-12-31 13F/A-1 MARTIN MARIETTA MATLS COM 573284106 104,188 91,531 723.17 23,113 904.48 0.0591
2017-02-13 2016-12-31 13F MARTIN MARIETTA MATLS COM 573284106 104,188 23,113
2016-11-07 2016-09-30 13F MARTIN MARIETTA MATERIALS Com 573284106 12,657 -187 -1.46 2,301 -4.01 0.0342
2016-08-03 2016-06-30 13F MARTIN MARIETTA MATERIALS Com 573284106 12,844 6,242 94.55 2,397 133.63 0.0360
2016-05-05 2016-03-31 13F MARTIN MARIETTA MATERIALS Com 573284106 6,602 1,300 24.52 1,026 38.27 0.0150
2016-01-28 2015-12-31 13F MARTIN MARIETTA MATERIALS Com 573284106 5,302 0 0.00 742 -5.96 0.0111
2015-11-12 2015-09-30 13F MARTIN MARIETTA MATERIALS Com 573284106 5,302 -601 -10.18 789 -5.85 0.0120
2015-08-06 2015-06-30 13F MARTIN MARIETTA MATERIALS Com 573284106 5,903 0 0.00 838 -0.24 0.0116
2015-05-11 2015-03-31 13F MARTIN MARIETTA MATERIALS COM 573284106 5,903 0 0.00 840 27.47 0.0104
2015-02-09 2014-12-31 13F MARTIN MARIETTA MATERIALS COM 573284106 5,903 0 0.00 659 -13.74 0.0086
2014-11-05 2014-09-30 13F MARTIN MARIETTA MATERIALS COM 573284106 5,903 177 3.09 764 1.06 0.0105
2014-08-12 2014-06-30 13F MARTIN MARIETTA MATERIALS COM 573284106 5,726 0 0.00 756 3.99 0.0113
2014-05-05 2014-03-31 13F MARTIN MARIETTA MATERIALS COM 573284106 5,726 0 0.00 727 28.22 0.0115
2014-02-05 2013-12-31 13F/A-1 MARTIN MARIETTA MATERIALS COM 573284106 5,726 -35 -0.61 567 1.61 0.0088
2014-01-29 2013-12-31 13F MARTIN MARIETTA MATERIALS COM 573284106 5,726 567
2014-02-05 2013-09-30 13F/A-1 MARTIN MARIETTA MATERIALS Com 573284106 5,761 624 12.15 558 8.14 0.0084
2013-11-06 2013-09-30 13F MARTIN MARIETTA MATERIALS Com 573284106 5,761 558
2014-02-12 2013-06-30 13F/A-1 MARTIN MARIETTA MATERIALS Com 573284106 5,137 5,137 516 0.0084
2013-08-05 2013-06-30 13F MARTIN MARIETTA MATERIALS Com 573284106 5,137 516
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.