Martin Marietta Materials, Inc.
| Security | MX:MLM / Martin Marietta Materials, Inc. |
| Institution | Rathbone Brothers plc |
| Latest Disclosed Ownership | 162,991 shares |
| Latest Disclosed Value | $ 95,949,541 |
Rathbone Brothers plc reports 17.76% decrease in ownership of MLM / Martin Marietta Materials, Inc.
On May 12, 2026 - Rathbone Brothers plc filed a 13F-HR form disclosing ownership of 162,991 shares of Martin Marietta Materials, Inc. (MX:MLM) valued at $95,949,541 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on February 6, 2026 disclosing 198,201 shares of Martin Marietta Materials, Inc.. This represents a change in shares of -17.76% 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 MATERIALS USD0.01 | COM | 573284106 | 162,991 | -35,210 | -17.76 | 95,950 | -22.25 | 0.4100 | |||||
| 2026-02-06 | 2025-12-31 | 13F/A-1 | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 198,201 | -3,875 | -1.92 | 123,412 | -3.10 | 0.4885 | |||||
| 2026-01-21 | 2025-12-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 198,201 | -3,875 | 123,412 | 0.4885 | |||||||
| 2025-11-13 | 2025-09-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 202,076 | -10 | -0.00 | 127,364 | 14.81 | 0.5172 | |||||
| 2025-08-07 | 2025-06-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 202,086 | -1,867 | -0.92 | 110,937 | 13.76 | 0.4785 | |||||
| 2025-05-13 | 2025-03-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 203,953 | -1,299 | -0.63 | 97,516 | -8.01 | 0.4712 | |||||
| 2025-02-13 | 2024-12-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 205,252 | -7,577 | -3.56 | 106,013 | -7.46 | 0.5132 | |||||
| 2024-11-13 | 2024-09-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 212,829 | 34 | 0.02 | 114,555 | -0.64 | 0.5781 | |||||
| 2024-08-09 | 2024-06-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 212,795 | 321 | 0.15 | 115,292 | -11.62 | 0.6279 | |||||
| 2024-05-14 | 2024-03-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 212,474 | -253 | -0.12 | 130,446 | 22.91 | 0.7528 | |||||
| 2024-02-13 | 2023-12-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 212,727 | -250 | -0.12 | 106,132 | 21.40 | 0.6840 | |||||
| 2023-11-13 | 2023-09-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 212,977 | 602 | 0.28 | 87,423 | -10.84 | 0.6340 | |||||
| 2023-08-04 | 2023-06-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 212,375 | -39,976 | -15.84 | 98,051 | 9.43 | 0.9151 | |||||
| 2023-05-12 | 2023-03-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 252,351 | 251 | 0.10 | 89,600 | 5.16 | 0.9161 | |||||
| 2023-02-14 | 2022-12-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 252,100 | -114 | -0.05 | 85,202 | 4.88 | 0.9593 | |||||
| 2022-11-14 | 2022-09-30 | 13F/A-1 | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 252,214 | 114 | 0.05 | 81,236 | 7.69 | 1.0023 | |||||
| 2022-11-03 | 2022-09-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 252,214 | 114 | 81,236 | 1.0023 | |||||||
| 2022-08-12 | 2022-06-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 252,100 | -1,600 | -0.63 | 75,438 | -22.74 | 0.8648 | |||||
| 2022-05-11 | 2022-03-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 253,700 | 0 | 0.00 | 97,647 | -12.63 | 0.9963 | |||||
| 2022-02-10 | 2021-12-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 253,700 | 0 | 0.00 | 111,760 | 28.93 | 1.0861 | |||||
| 2021-11-04 | 2021-09-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 253,700 | 30,900 | 13.87 | 86,684 | 10.59 | 0.9326 | |||||
| 2021-07-30 | 2021-06-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 222,800 | 0 | 0.00 | 78,383 | 4.76 | 0.8708 | |||||
| 2021-05-14 | 2021-03-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 222,800 | 1,500 | 0.68 | 74,821 | 19.06 | 0.9581 | |||||
| 2021-02-11 | 2020-12-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 221,300 | 0 | 0.00 | 62,843 | 20.65 | 0.8922 | |||||
| 2020-11-13 | 2020-09-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 221,300 | 30,800 | 16.17 | 52,085 | 32.36 | 0.8912 | |||||
| 2020-08-07 | 2020-06-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 190,500 | 73,800 | 63.24 | 39,352 | 78.20 | 0.7989 | |||||
| 2020-05-04 | 2020-03-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 116,700 | 0 | 0.00 | 22,083 | -32.33 | 0.6432 | |||||
| 2020-02-11 | 2019-12-31 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 116,700 | 13,700 | 13.30 | 32,634 | 15.59 | 0.8591 | |||||
| 2019-11-13 | 2019-09-30 | 13F | MARTIN MARIETTA MATERIALS USD0.01 | COM | 573284106 | 103,000 | 103,000 | 28,232 | 0.8018 |
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.
