MARTIN MARIETTA MATERIALS (MLM) Top Institutional Shareholders
MARTIN MARIETTA MATERIALS (MLM) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended March 31, 2026. The institutional investors covered on this page collectively reported approximately $432.40M in MLM holdings during the latest filing period.
Gardner Russo & Quinn is currently the largest disclosed institutional shareholder of MLM tracked by InsiderSet, reporting ownership valued at approximately $421.15M in its March 31, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $422.87M, representing an estimated gain of +0.41% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 100% of the total disclosed MLM value among the investors covered in this analysis. Major shareholders include Gardner Russo & Quinn, Sequoia Financial Advisors, Lountzis Asset Management, and several other long-term asset managers with concentrated positions in MARTIN MARIETTA MATERIALS (MLM).
This page ranks the largest institutional MLM shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Gardner Russo & Quinn | Thomas Russo | 4.96% | 715,411 | $421,148,042 | $422,865,134 | +$1,717,092 | +0.41% |
| Sequoia Financial Advisors | 0.03% | 10,326 | $6,078,697 | $6,103,492 | +$24,795 | +0.41% | |
| Lountzis Asset Management | Paul Lountzis | 1.80% | 8,325 | $4,900,761 | $4,920,741 | +$19,980 | +0.41% |
| Eagle Capital Management | Ravenel Boykin Curry IV | 0.00% | 470 | $276,514 | $277,808 | +$1,294 | +0.47% |
Frequently asked questions about MLM
Who owns the most MLM stock?
The largest holders of MLM are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for MARTIN MARIETTA MATERIALS (MLM).
Is MLM widely held by superinvestors?
Many widely followed stocks like MLM appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly MLM is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.