Among active 13F managers last quarter, 12 opened and 21 added, while 21 reduced; the largest holder to move was American Century Companies Inc (+69%). Over the last 180 days, 6 insiders sold and none bought, a net -$10.9M in open-market trades.
The legs disagree, or only one of them leans.
344 tracked 13F filers disclose a position in MTRN as of the latest SEC 13F filings, a combined $4.4B in reported value. Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.
| # | Fund | Shares | Position value | Last move | As of | History |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 3.5M | $1.0B | ▲+3.1% Added · +105K sh | Q2 2026 | |
| 2 | State Street Corp | 1.5M | $433.0M | ▲+9.6% Added · +128K sh | Q2 2026 | |
| 3 | Vanguard Portfolio Management LLC | 1.4M | $415.3M | ▲+3.5% Added · +47K sh | Q2 2026 | |
| 4 | Vanguard Capital Management LLC | 938K | $278.8M | ▲+1.0% Added · +10K sh | Q2 2026 | |
| 5 | Dimensional Fund Advisors LP | 885K | $128.0M | ▼−11% Reduced · −106K sh | Q1 2026 | |
| 6 | American Century Companies Inc | 883K | $127.7M | ▲+69% Added · +361K sh | Q1 2026 | |
| 7 | Geode Capital Management, LLC | 591K | $175.8M | ▲+17% Added · +87K sh | Q2 2026 | |
| 8 | Barrow Hanley Mewhinney & Strauss LLC | 530K | $76.6M | ▼−6.0% Reduced · −34K sh | Q1 2026 | |
| 9 | Fisher Asset Management, LLC | 442K | $63.9M | ▲+215% Added · +302K sh | Q1 2026 | |
| 10 | Morgan Stanley | 424K | $61.4M | ▼−1.2% Reduced · −5K sh | Q1 2026 | |
| 11 | Price T Rowe Associates Inc | 329K | $97.9M | ▲13× Added · +305K sh | Q2 2026 | |
| 12 | Segall Bryant & Hamill, LLC | 314K | $93.4M | ▼−6.1% Reduced · −20K sh | Q2 2026 | |
| 13 | Raymond James Financial Inc | 293K | $40.6M | ▲+1.6% Added · +5K sh | Q1 2026 | |
| 14 | Charles Schwab Investment Management Inc | 293K | $42.3M | ▼−3.7% Reduced · −11K sh | Q1 2026 | |
| 15 | Mirae Asset Global Etfs Holdings Ltd. | 261K | $37.7M | ▼−11% Reduced · −33K sh | Q1 2026 | |
| 16 | Northern Trust Corp | 248K | $35.8M | ▼−0.6% Reduced · −2K sh | Q1 2026 | |
| 17 | Copeland Capital Management, LLC | 228K | $67.7M | ▼−14% Reduced · −38K sh | Q2 2026 | |
| 18 | Harvey Partners, LLC | 220K | $65.4M | ▼−25% Reduced · −73K sh | Q2 2026 | |
| 19 | Royal Bank Of Canada | 219K | $31.7M | ▼−15% Reduced · −38K sh | Q1 2026 | |
| 20 | Gamco Investors, Inc. Et Al | 191K | $27.7M | ▼−2.4% Reduced · −5K sh | Q1 2026 | |
| 21 | JPMorgan Chase & Co | 183K | $25.2M | ▲+10% Added · +17K sh | Q1 2026 | |
| 22 | Kennedy Capital Management LLC | 166K | $24.0M | ▲+0.8% Added · +1K sh | Q1 2026 | |
| 23 | Aberdeen Group plc | 164K | $23.8M | ▼−16% Reduced · −32K sh | Q1 2026 | |
| 24 | Bank of New York Mellon Corp | 152K | $22.1M | ▼−2.9% Reduced · −5K sh | Q1 2026 | |
| 25 | Samlyn Capital, LLC | 152K | $45.1M | ▲New +152K sh | Q2 2026 |
Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership. 2 value rows are withheld because the reported units disagree with same-security peers; share counts are unchanged.
Last quarter, 12 funds opened a new position in MTRN and 21 added to an existing one, while 21 reduced. Based on 13F filings from active, signal-eligible managers (passive index funds and other mechanical holders are excluded from this count).
| Company | Co-held by | Their position there |
|---|---|---|
| Microsoft CorpMSFT | 187 funds | $233.2B |
| Amazon.com IncAMZN | 187 funds | $178.5B |
| Apple IncAAPL | 186 funds | $269.5B |
| Alphabet Inc-CL AGOOGL | 186 funds | $167.0B |
| Meta Platforms Inc-Class AMETA | 184 funds | $98.3B |
| Nvidia CorpNVDA | 183 funds | $360.5B |
| JPMorgan Chase & CoJPM | 183 funds | $59.4B |
| Broadcom IncAVGO | 181 funds | $146.8B |
| Eli Lilly & CoLLY | 179 funds | $77.7B |
| Alphabet Inc-CL CGOOG | 177 funds | $117.7B |
| Micron Technology IncMU | 176 funds | $47.9B |
| Johnson & JohnsonJNJ | 176 funds | $43.1B |
Ranked by how many of MTRN's tracked holders also hold each name. The last column is those co-holders' combined reported position in that name, not in MTRN.
| Date | Insider | Role | Action | Shares | Value |
|---|---|---|---|---|---|
| Sep 1, 2026 | Liggett Emily M | Director | Sell (S) | 1K | $235K |
| Aug 31, 2026 | Khilnani Vinod M | Director | Sell (S) | 2K | $470K |
| Aug 7, 2026 | Vijayvargiya Jugal K. | President and CEO, Director | Sell (S) 8 lots, same day | 24K | $7.1M |
| Aug 7, 2026 | Chadwick Shelly Marie | Vice President, Finance & CFO | Sell (S) | 2K | $500K |
| Aug 7, 2026 | Solomon Darlene J. S. | Director | Sell (S) | 4K | $1.1M |
| May 29, 2026 | Phillippy Robert J | Director | Sell (S) 4 lots, same day | 4K | $765K |
| May 13, 2026 | Khilnani Vinod M | Director | Sell (S) 4 lots, same day | 3K | $517K |
| May 8, 2026 | Chadwick Shelly Marie | Vice President, Finance & CFO | Sell (S) | 1K | $237K |
| Mar 3, 2026 | Chemnitz Gregory R. | VP General Counsel & Secretary | Sell (S) 2 lots, same day | 5K | $711K |
| Mar 3, 2026 | Fashinpaur Melissa A | Chief Accounting Officer | Sell (S) | 309 | $49K |
| Mar 3, 2026 | Chadwick Shelly Marie | Vice President, Finance & CFO | Sell (S) 2 lots, same day | 3K | $406K |
| Feb 23, 2026 | Chadwick Shelly Marie | Vice President, Finance & CFO | Sell (S) 2 lots, same day | 9K | $1.3M |
One row per insider, day and transaction code; shares and value are summed across the lots. Every lot is on the full insider page and in the filing.
Where institutional funds (13F), corporate insiders (Form 4) and US House members (STOCK Act) are buying or selling the same name in the same window. Green is buying, red is selling.
Insiders and Congress: last 180 days. Funds: latest 13F, top 100 holders incl. passive
| Source | Buying | Selling | Net |
|---|---|---|---|
13F funds Top 100 holders by value, passive included; the hero counts active managers only | 43 | 42 | – |
Insiders Form 4 open-market | 0 | 6 | -$10.9M |
US House STOCK Act trades | 0 | 0 | $0 |
Capital Rotation reports where institutional capital disclosed rotating, as of the latest public SEC 13F filings. It is data, not investment advice, a recommendation, or a prediction. Filings lag about 45 days and cover long US equity positions only. Past disclosed flows do not indicate future prices. Do your own research; consult a licensed advisor.
Connected entities for MTRN
This stock page is the public Follow view. For one current, evidence-backed answer, use capital_change_brief through REST or MCP. It compares tracked 13F changes with qualifying Form 4 activity and cites the SEC evidence.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/stocks/MTRN/capital-change-brief"
Use Arkolith's capital_change_brief for MTRN. Tell me what changed, whether insider activity corroborates it, and cite the SEC evidence.
13F holdings + Form 4 insider transactions + end-of-day price history + the live filing stream, joined for MTRN. Filings are public domain, sourced to SEC EDGAR; price series derived from end-of-day closes.