Peconic Partners LLC · Q2 2026 13F · SEC CIK 1050464
William Harnisch portfolio
Hedge fundPeconic Partners 13F holdings. Filed 2026-08-14 for Q2 2026. Open the filing ↗ · All SEC filings ↗
- Reported 13F value
- $7.5B
- Reported positions
- 7
- Top holdings a year, 3 yrs
- +51.6%
- Assets under management
- $2.7B
William Harnisch is the founder of Peconic Partners, which reported 7 positions worth $7.5B in its Q2 2026 13F, filed 2026-08-14. Its largest holdings were Quanta Svcs Inc (PWR, 45.2%), Dycom Inds Inc (DY, 29.9%), MasTec Inc (MTZ, 20.3%). A portfolio copying its top holdings returned 51.6% a year over the last 3 years, against 20.4% for the S&P 500.
William Harnisch holdings all 7 positions.
Weights are shares of the filer's total reported 13F value, compared with Q1 2026. Share changes may reflect splits; weight changes also reflect price moves. A 13F shows long US-listed positions only, up to 135 days after the fact.
| Stock | % of 13F value | Share change | Reported value |
|---|---|---|---|
| PWRQuanta Svcs Inc | 45.2% | -5.7% | $3.4B |
| DYDycom Inds Inc | 29.9% | +8.0% | $2.2B |
| MTZMasTec Inc | 20.3% | +2.8% | $1.5B |
| FCXFreeport Mcmoran Inc | 3.3% | +18.1% | $246.3M |
| AMCAmc Entmt Hldgs Inc | 0.8% | +966.7% | $60.8M |
| CNKCinemark Hldgs Inc | 0.5% | +200.5% | $38.1M |
| GOOGLAlphabet Inc | 0.0% | +0.0% | $643K |
What William Harnisch bought and sold in Q2 2026, against Q1 2026.
New positions
No new positions among the largest holdings.
Added to
- AMC Amc Entmt Hldgs Inc+966.7% shares
- CNK Cinemark Hldgs Inc+200.5% shares
- FCX Freeport Mcmoran Inc+18.1% shares
- DY Dycom Inds Inc+8.0% shares
Reduced
- PWR Quanta Svcs Inc-5.7% shares
Sold out
- AMZN Amazon Com Incwas 3.4%
- FSLR First Solar Incwas 1.3%
Share counts compared with the Q1 2026 13F; a split also changes share counts.
How the holdings did against the S&P 500.
- 1 year
- +73.5% /yr
- S&P 500 +20.1%
- 3 years
- +51.6% /yr
- S&P 500 +20.4%
- 5 years
- +41.7% /yr
- S&P 500 +11.6%
A portfolio of the filer's 20 largest 13F positions, weighted by value, bought the trading day after each 13F was filed and held until the next one was: what copying this filer could have earned. 13Fs show long US-listed positions only, so this is an estimate of the stock picks, not the fund's reported returns.
Reported 13F value by quarter.
| Quarter | 13F value | Positions |
|---|---|---|
| Q2 2026 | $7.5B | 7 |
| Q1 2026 | $5.8B | 9 |
| Q4 2025 | $4.2B | 15 |
| Q3 2025 | $3.6B | 12 |
| Q2 2025 | $3.1B | 11 |
| Q1 2025 | $2.0B | 7 |
| Q4 2024 | $2.5B | 12 |
| Q3 2024 | $2.4B | 6 |
| Q2 2024 | $2.3B | 11 |
| Q1 2024 | $2.3B | 10 |
| Q4 2023 | $2.1B | 9 |
| Q3 2023 | $1.7B | 8 |
Questions about William Harnisch's portfolio
Who is William Harnisch?
William Harnisch is the founder of Peconic Partners, a hedge fund that files its US stock holdings with the SEC on Form 13F under the name Peconic Partners LLC.
What stocks does William Harnisch own?
Peconic Partners LLC's latest 13F, for Q2 2026 and filed Aug 14, 2026, lists 7 positions worth $7.5B. The largest are Quanta Svcs Inc (PWR) at 45.2%, Dycom Inds Inc (DY) at 29.9%, MasTec Inc (MTZ) at 20.3%, Freeport Mcmoran Inc (FCX) at 3.3% and Amc Entmt Hldgs Inc (AMC) at 0.8%.
What did William Harnisch buy last quarter?
In Q2 2026, Peconic Partners LLC added Amc Entmt Hldgs Inc (AMC) (+966.7% shares), Cinemark Hldgs Inc (CNK) (+200.5% shares) and Freeport Mcmoran Inc (FCX) (+18.1% shares), compared with its Q1 2026 filing.
What did William Harnisch sell last quarter?
In Q2 2026, Peconic Partners LLC sold all of Amazon Com Inc (AMZN), sold all of First Solar Inc (FSLR) and Quanta Svcs Inc (PWR) (-5.7% shares), compared with its Q1 2026 filing.
How has William Harnisch's portfolio performed?
A portfolio copying Peconic Partners LLC's 20 largest 13F holdings each quarter, from the day each filing was public, returned +51.6% a year over the last 3 years, against +20.4% for the S&P 500. Over 1 year: +73.5% against +20.1%. Over 5 years: +41.7% a year against +11.6%.
When is Peconic Partners LLC's next 13F filing due?
13F filings are due 45 days after each quarter ends. Peconic Partners LLC's filing for the quarter ending Sep 30, 2026 is due by Nov 14, 2026; this page updates the day after it is published.
How much money does Peconic Partners LLC manage?
Peconic Partners LLC reported $2.7B of regulatory assets under management on its latest SEC Form ADV. Its 13F, which covers only US-listed stocks and options, totals $7.5B.