Martin Marietta Materials, Inc.
MX ˙ BMV ˙ US5732841060
SecurityMX:MLM / Martin Marietta Materials, Inc.
InstitutionSchroder Investment Management Group
Latest Disclosed Ownership6,514 shares
Latest Disclosed Value $ 3,834,662
Schroder Investment Management Group reports 2.73% increase in ownership of MLM / Martin Marietta Materials, Inc.

On May 14, 2026 - Schroder Investment Management Group filed a 13F-HR form disclosing ownership of 6,514 shares of Martin Marietta Materials, Inc. (MX:MLM) valued at $3,834,662 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 6,341 shares of Martin Marietta Materials, Inc.. This represents a change in shares of 2.73% 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)
2026-05-14 2026-03-31 13F MARTIN MARIETTA MATLS COM 573284106 6,514 173 2.73 3,835 -2.89 0.0006
2026-02-13 2025-12-31 13F MARTIN MARIETTA MATLS COM 573284106 6,341 -998 -13.60 3,948 -14.64 0.0030
2025-11-13 2025-09-30 13F MARTIN MARIETTA MATLS COM 573284106 7,339 724 10.94 4,626 27.38 0.0036
2025-08-13 2025-06-30 13F MARTIN MARIETTA MATLS COM 573284106 6,615 -119 -1.77 3,631 12.80 0.0031
2025-05-13 2025-03-31 13F MARTIN MARIETTA MATLS COM 573284106 6,734 0 0.00 3,220 -7.45 0.0033
2025-02-12 2024-12-31 13F MARTIN MARIETTA MATLS COM 573284106 6,734 -501 -6.92 3,478 -10.68 0.0033
2024-11-13 2024-09-30 13F MARTIN MARIETTA MATLS COM 573284106 7,235 -4,181 -36.62 3,894 -37.04 0.0040
2024-08-12 2024-06-30 13F MARTIN MARIETTA MATLS COM 573284106 11,416 1,401 13.99 6,185 0.60 0.0068
2024-05-14 2024-03-31 13F MARTIN MARIETTA MATLS COM 573284106 10,015 802 8.71 6,149 33.77 0.0072
2024-02-14 2023-12-31 13F MARTIN MARIETTA MATLS COM 573284106 9,213 1,641 21.67 4,596 47.88 0.0060
2023-11-14 2023-09-30 13F MARTIN MARIETTA MATLS COM 573284106 7,572 265 3.63 3,108 -7.86 0.0046
2023-08-11 2023-06-30 13F MARTIN MARIETTA MATLS COM 573284106 7,307 332 4.76 3,374 36.23 0.0048
2023-05-11 2023-03-31 13F MARTIN MARIETTA MATLS COM 573284106 6,975 -1,397 -16.69 2,477 -12.48 0.0037
2023-02-10 2022-12-31 13F MARTIN MARIETTA MATLS COM 573284106 8,372 542 6.92 2,829 12.13 0.0045
2022-11-14 2022-09-30 13F MARTIN MARIETTA MATLS COM 573284106 7,830 1,748 28.74 2,523 38.10 0.0042
2022-08-11 2022-06-30 13F MARTIN MARIETTA MATLS COM 573284106 6,082 2,392 64.82 1,827 26.88 0.0028
2022-05-16 2022-03-31 13F MARTIN MARIETTA MATLS COM 573284106 3,690 1,570 74.06 1,440 54.18 0.0019
2022-02-14 2021-12-31 13F Martin Marietta Materials COM 573284106 2,120 -470 -18.15 934 5.54 0.0012
2021-11-12 2021-09-30 13F MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 2,590 -1,268 -32.87 885 -34.78 0.0014
2021-08-13 2021-06-30 13F MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 3,858 693 21.90 1,357 27.66 0.0017
2021-05-28 2021-03-31 13F/A-1 MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 3,165 1,871 144.59 1,063 0.0014
2021-05-17 2021-03-31 13F MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 3,165 1,871 1,063 0.0014
2021-02-24 2020-12-31 13F/A-1 MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 1,294 -37 -2.78 0 -100.00 0.0005
2021-02-16 2020-12-31 13F MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 1,294 -37 0 0.0005
2020-11-13 2020-09-30 13F MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 1,331 -116 -8.02 320 7.02 0.0005
2020-08-13 2020-06-30 13F MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 1,447 -215 -12.94 299 1.70 0.0005
2020-05-15 2020-03-31 13F MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 1,662 1,447 673.02 294 390.00 0.0006
2020-02-11 2019-12-31 13F MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 215 0 0.00 60 3.45 0.0001
2019-11-12 2019-09-30 13F MARTIN MARIETTA MATERIALS INCORPORATED USD0.01 COM 573284106 215 -175,297 -99.88 58 -99.67 0.0001
2014-02-14 2013-12-31 13F MartinMariet.Mat.ComStkUSD0.01 COM 573284106 175,512 31,900 22.21 17,541 24.41 0.0219
2013-12-09 2013-09-30 13F/A-1 MartinMariet.Mat.ComStkUSD0.01 COM 573284106 14,098,390 13,957,078 1,384,039 0.0417
2013-12-10 2013-09-30 13F/A-2 MartinMariet.Mat.ComStkUSD0.01 COM 573284106 143,612 2,300 1.63 14,098 1.37 0.0342
2013-11-08 2013-09-30 13F MartinMariet.Mat.ComStkUSD0.01 COM 573284106 143,612 2,300 14,098 34.7897
2013-08-12 2013-06-30 13F MartinMariet.Mat.ComStkUSD0.01 COM 573284106 141,312 141,312 13,908 0.0368
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.