Martin Marietta Materials, Inc.
US ˙ NYSE ˙ US5732841060

SecurityMLM / Martin Marietta Materials, Inc.
InstitutionTarbox Family Office, Inc.
Latest Disclosed Ownership1,102 shares
Latest Disclosed Value $ 648,725
Tarbox Family Office, Inc. reports 4.67% decrease in ownership of MLM / Martin Marietta Materials, Inc.

On April 23, 2026 - Tarbox Family Office, Inc. filed a 13F-HR form disclosing ownership of 1,102 shares of Martin Marietta Materials, Inc. (US:MLM) valued at $648,725 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 21, 2026 disclosing 1,156 shares of Martin Marietta Materials, Inc.. This represents a change in shares of -4.67% during the quarter. The current value of the position is $642,631 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)
2026-04-23 2026-03-31 13F MARTIN MARIETTA MATLS COM 573284106 1,102 -54 -4.67 649 -9.87 0.1054
2026-01-21 2025-12-31 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 720 -1.24 0.1158
2025-10-24 2025-09-30 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 729 14.83 0.1070
2025-08-12 2025-06-30 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 635 14.86 0.0954
2025-05-08 2025-03-31 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 553 -7.54 0.0919
2025-01-17 2024-12-31 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 597 -4.02 0.0985
2024-10-23 2024-09-30 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 622 -0.64 0.1020
2024-07-17 2024-06-30 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 626 -11.71 0.1105
2024-04-16 2024-03-31 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 710 23.09 0.1247
2024-02-08 2023-12-31 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 577 21.52 0.1122
2023-10-13 2023-09-30 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 475 -11.07 0.0983
2023-07-20 2023-06-30 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 534 30.00 0.1038
2023-04-11 2023-03-31 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 410 5.13 0.0829
2023-01-25 2022-12-31 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 391 12.72 0.0856
2022-10-14 2022-09-30 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 346 0.00 0.0821
2022-07-19 2022-06-30 13F MARTIN MARIETTA MATLS COM 573284106 1,156 0 0.00 346 -22.25 0.0777
2022-04-25 2022-03-31 13F MARTIN MARIETTA MATLS COM 573284106 1,156 -10 -0.86 445 -13.42 0.0903
2022-01-06 2021-12-31 13F MARTIN MARIETTA MATLS COM 573284106 1,166 0 0.00 514 29.15 0.0885
2021-10-12 2021-09-30 13F MARTIN MARIETTA MATLS COM 573284106 1,166 0 0.00 398 -2.93 0.0729
2021-07-16 2021-06-30 13F MARTIN MARIETTA MATLS COM 573284106 1,166 0 0.00 410 4.59 0.0733
2021-04-27 2021-03-31 13F MARTIN MARIETTA MATLS COM 573284106 1,166 0 0.00 392 18.43 0.0771
2021-01-27 2020-12-31 13F MARTIN MARIETTA MATLS COM 573284106 1,166 0 0.00 331 20.80 0.0692
2020-10-22 2020-09-30 13F MARTIN MARIETTA MATLS COM 573284106 1,166 -101 -7.97 274 4.58 0.0667
2020-07-23 2020-06-30 13F MARTIN MARIETTA MATLS COM 573284106 1,267 77 6.47 262 16.44 0.0678
2020-04-30 2020-03-31 13F MARTIN MARIETTA MATLS COM 573284106 1,190 23 1.97 225 -30.98 0.0729
2020-01-31 2019-12-31 13F MARTIN MARIETTA MATLS COM 573284106 1,167 4 0.34 326 2.19 0.0890
2019-10-25 2019-09-30 13F MARTIN MARIETTA MATLS COM 573284106 1,163 0 0.00 319 19.03 0.0970
2019-08-02 2019-06-30 13F MARTIN MARIETTA MATLS COM 573284106 1,163 4 0.35 268 15.02 0.0838
2019-04-24 2019-03-31 13F MARTIN MARIETTA MATLS COM 573284106 1,159 0 0.00 233 17.09 0.0852
2019-02-01 2018-12-31 13F MARTIN MARIETTA MATLS COM 573284106 1,159 44 3.95 199 -1.97 0.0824
2018-10-26 2018-09-30 13F MARTIN MARIETTA MATLS COM 573284106 1,115 0 0.00 203 -18.47 0.0734
2018-07-31 2018-06-30 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 1,115 3 0.27 249 7.79 0.0960
2018-04-24 2018-03-31 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 1,112 0 0.00 231 -6.10 0.0892
2018-01-26 2017-12-31 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 1,112 0 0.00 246 7.42 0.0976
2017-10-19 2017-09-30 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 1,112 0 0.00 229 -7.66 0.1004
2017-07-18 2017-06-30 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 1,112 1,100 9,166.67 248 8,166.67 0.1223
2017-04-28 2017-03-31 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 12 0 0.00 3 0.00 0.0015
2017-01-31 2016-12-31 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 12 0 0.00 3 50.00 0.0017
2016-10-28 2016-09-30 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 12 0 0.00 2 0.00 0.0013
2016-07-29 2016-06-30 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 12 0 0.00 2 0.00 0.0014
2016-04-27 2016-03-31 13F MARTIN MARIETTA MATLS INC COM Stock 573284106 12 12 2 0.0015
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.