Martin Marietta Materials, Inc.

The full register, from 13F filings

The Register tab above is hand research: a dozen holders, each traced to the filing it came from. This asks the same question of the whole market for the quarter ended 31-mar-2026, where 1,057 managers reported a position. Broad where the research is deep, and shallow in the ways a 13F always is.

Built from 13F filings, which report US listed, long, US custodied positions only. A register from this source is a floor rather than a level: a holder's true position can be far larger, as BlackRock's ASML stake shows at 1.28m shares in a 13F against 26.3m in its 13G/A. Holdings held through derivatives, outside US custody, or below a manager's reporting obligation do not appear. Where a holder is marked as a family, its total sums several separate filing entities and describes something no single filing describes; the constituent entities and their share counts are listed so the total can be checked. That roll-up can legitimately exceed the family's own Schedule 13G, because a 13G is filed by one legal entity: Vanguard reports Alphabet through ten advisory entities, and The Vanguard Group Inc itself reported zero after its January 2026 disaggregation.

What a reader needs to know to read these numbers

• Holdings side is an empty array, which is a sourced finding, not a gap. The FY2025 10-K (filed 19 Feb 2026) and the Q2 2026 10-Q (filed 30 Jul 2026, covering the quarter ended 30 Jun 2026) were both searched in full for 'equity method', 'unconsolidated', 'joint venture', 'noncontrolling interest', 'affiliate', 'nonconsolidated', '50%', '49%', 'majority-owned', 'minority interest', 'partially-owned', 'significant influence' and 'cost method'. Unlike Nucor, Martin Marietta's 10-K carries no dedicated Investments or Equity Method Investments note: its Notes to Financial Statements run Note A through Note T with no gap, none titled Investments or Affiliates. Total noncontrolling interests on the consolidated balance sheet were $2 million at both 31 Dec 2025 and 30 Jun 2026 (versus total equity of $10.0-11.5 billion), too small to represent a materially sized consolidated majority-owned joint venture of the Nucor-Yamato/California Steel Industries type. The only textual evidence of any partially-owned affiliate is (a) a generic accounting-policy sentence that 'partially-owned affiliates are either consolidated or accounted for using the cost method or the equity method depending on the level of ownership interest', with no names or percentages attached, and (b) a small non-GAAP EBITDA reconciliation line, 'earnings/loss from nonconsolidated equity affiliates', which carries no disclosed balance, name, or ownership percentage anywhere in either filing searched.
• Two items were investigated and explicitly excluded as NOT equity stakes in another company. (1) Renewable-energy tax-equity investments in limited liability companies (RETC projects): the Company had committed to an additional $51 million of these investments at 31 Dec 2025 (recorded in the 'Unpaid commitments to limited liability companies' balance-sheet line) and invested $128 million of cash in such LLCs in 2025 per the cash flow statement; these are accounted for under the proportional amortization method purely to capture renewable-energy tax credits, not operating-company equity stakes, so they are excluded per the brief's guidance on excluding non-equity-stake items. (2) Mineral reserves and interests ($6.5 billion, within Property, Plant and Equipment) are quarries and mineral deposits Martin Marietta owns and operates directly, not equity stakes in other companies, and are excluded for the same reason the brief flags as the obvious way to get an aggregates producer wrong.
• Current status was checked, not assumed. Neither 'Texas Lehigh' nor any other historically plausible cement-industry joint-venture name was found in the FY2025 10-K. On 23 Feb 2026 the Company completed an asset exchange with QUIKRETE Holdings, Inc. (private): Martin Marietta received 100%-owned aggregates operations (~20 million tons/year in Virginia, Missouri, Kansas and Vancouver BC), a Vancouver asphalt and paving business, and $450 million cash; in exchange QUIKRETE received Martin Marietta's wholly owned Midlothian cement plant, related terminals, Texas ready-mixed concrete assets and certain nonoperating land. Both sides received wholly owned assets outright (an after-tax gain of $1.4 billion was booked on the divestiture); no equity interest in QUIKRETE, or by QUIKRETE in Martin Marietta, was created, so this is a wholly-owned asset swap and not a holding under the brief's definition.
• Register: computed against 60,065,839 common shares outstanding as of 27 Jul 2026 (Q2 2026 10-Q cover page, 'latest practicable date'), used as a single consistent denominator across the file, including the proxy-sourced insider rows.
• Per chunk learning #2, the fresh Q2 2026 13F (period 30 Jun 2026) was used for Vanguard and BlackRock rather than the 2026 proxy's own 5%-holder table, which cites stale Schedule 13G/A filings reporting beneficial ownership as of 31 Dec 2023 (filed Feb 2024 and Jan 2024 respectively): Vanguard 7,168,589 shares/11.9% and BlackRock 4,113,718 shares/7.0% per the proxy, versus 7,740,764 shares/12.89% and 4,692,446 shares/7.81% from the fresh 13F. The proxy's own text states 'no person beneficially owned more than 5%... except for those shown below', naming only Vanguard and BlackRock as of 6 Mar 2026; the fresh Q2 13F shows State Street Corporation at 5.26%, just over that threshold, evidently either because State Street had not filed (or crossed 5% via) a Schedule 13G as of the proxy's record date, or because continuing share buybacks (60,309,739 shares at 31 Dec 2025 falling to 60,065,839 by 27 Jul 2026) pushed a roughly static State Street position above 5% only after the proxy was finalized. Recorded as an observation, not corrected as an error in the proxy.
• Vanguard Group Inc's parent CIK (0000102909) filed Form 13F-NT (a notice carrying no holdings) for the quarter ended 30 Jun 2026, confirmed directly against its EDGAR submissions feed, so per the PNC-style rule the 8 successor entities were summed rather than one substituted: Vanguard Capital Management LLC, Vanguard Portfolio Management LLC, Vanguard Fiduciary Trust Co, Vanguard Global Advisers LLC, Vanguard Asset Management Ltd, Vanguard Investments Australia Ltd, Vanguard Personalized Indexing Management LLC and Vanguard National Trust Co, together 7,740,764 shares, $4,464,098,600. Both T. Rowe Price registrants (Associates, CIK 0000080255, and Investment Management, CIK 0001897612) were checked and both hold MLM; both report values in thousands on their raw XML (the thousands trap), corrected here by rescaling x1000, verified against the ~$576.7-576.9/share cluster shown by every other filer on the same date.
• Implied-price check across every institutional row (Vanguard, BlackRock, State Street, FMR, Principal Financial Group and both T. Rowe Price entities) clusters tightly at $576.68-$576.85 per share for the 30 Jun 2026 quarter-end date (Geode is a slight outlier at $574.50, about 0.4% low, not large enough to suggest a units error). Martin Marietta has a genuinely high share price on a small share count (60,065,839 shares, versus roughly 3-10x that for most large-cap peers), so the resulting register values, and the company's own $522.81 close on 18 Aug 2026 implying a $31.40 billion market cap on only 60.07 million shares, are treated as correct rather than as a scaling error, per the brief's explicit instruction for a high-implied-price company; no evidence of a stock split was found (shares outstanding moved only modestly, 60,309,739 at 31 Dec 2025 to 60,065,839 at 27 Jul 2026, consistent with ongoing buybacks, not a split).
• Self-gate, computed from this final file the way the chart computes it (the 'All current Directors and executive officers as a group (17 individuals)' row reduced to its residual of 393,567 minus Nye's 246,438 = 147,129; every other row, including Nye himself, counted at full value): Vanguard 7,740,764 + BlackRock 4,692,446 + State Street 3,159,639 + T. Rowe Price 2,240,645 + FMR 2,192,603 + Principal Financial Group 2,116,369 + Geode 1,601,490 + Nye 246,438 + officers-group residual 147,129 = 24,137,523 shares against 60,065,839 shares outstanding, 40.19%, within the expected 25 to 45 percent range. 9 register rows total.
• Vanguard entities summed: 8 (see above), all individually confirmed on fresh 30 Jun 2026 13F-HR filings rather than assumed from the project's own pre-existing data/registers/MLM.json (which was used only to enumerate candidate entity names/CIKs for a Q1 2026-period file, then independently re-verified against Q2 2026 EDGAR filings for this register).