MTZ
Mastec Inc
3 super-investors hold MTZ worth a combined $686M. The largest position: Daniel Loeb at 4.9% of their portfolio. This quarter the cohort logged 1 buy and 1 sell on the name. Cohort Conviction Score: 28 — ranked #464 of 724 scored stocks. Conviction rising: 1 more super-investor hold it than in 2025Q4.
Why super-investors own MTZ
Stephen Mandel's new position — the largest in the cohort at $493M and 3.9% of his portfolio — is the defining development for MTZ this quarter, lifting the tracked owner count from two to three and driving combined cohort exposure to $686M. Daniel Loeb remains the highest-concentration holder at 4.9% ($103M) but trimmed during the period, suggesting some profit-taking or rebalancing rather than a thesis change. Joel Greenblatt holds a token 0.1% slice ($90M in dollar terms). The cohort has been slow-building — owner count was flat at one for several quarters before ticking up — making Mandel's sizable entry the clearest signal that institutional interest in the infrastructure contractor is now meaningfully broadening.
AI-synthesized from 13F filings. Not investment advice.
Cohort owners over time
2025Q3 → 2026Q1How many of the cohort members held this stock each quarter.
Owners (3) · click any column to sort
| #↑ | Manager | % Port. | History | Value | Shares |
|---|---|---|---|---|---|
| 1 | Stephen Mandel | 3.9% | — 1q | $493M | 1,531,050 |
| 2 | Daniel Loeb | 4.9% | 3q | $103M | 320,000 |
| 3 | Joel Greenblatt | 0.1% | 38q | $90M | 279,778 |
Owners of MTZ also hold
Recent activity (2)
| Manager | Move | % Port. | Δ Shares | Value | Filed |
|---|---|---|---|---|---|
| Daniel Loeb | TRIM | 4.9% | -65% | $103M | May 15, 2026 |
| Stephen Mandel | NEW | 3.9% | +100% | $493M | May 15, 2026 |
Long US equity 13F-HR filings only. CUSIP 576323109. Not investment advice.