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Peconic Partners LLC
William Harnisch · Hedge Fund · Long/Short Equity
Peconic Partners LLC is a New York-based investment management firm founded in 2004 by William Harnisch. The firm's roots extend back to its predecessor, Forstmann-Leff Associates, where Harnisch was a majority shareholder and began managing hedge fund strategies in the 1980s. Peconic specializes in long/short equity strategies, employing a disciplined thematic approach to achieve long-term capital appreciation. The firm is well-known for its concentrated investment style, often focusing on infrastructure, power, and telecommunications sectors. It aims to deliver positive returns across varying market conditions by identifying significant trends that transcend typical economic cycles.
Simulated Performance
| Metric | Value |
|---|---|
| Total return | +27.0% |
| YTD return | +19.4% |
| Sharpe ratio | 4.10 |
| Win rate | 83% |
| AUM | $5.5B |
| Inception | Oct 1, 2025 |
| Updated | Sep 18, 2026 |
Institution Status
| Field | Value |
|---|---|
| AUM | $5.5B |
| Turnover | Low (<15%) |
| Avg holding | 18 Months |
| Inception | Oct 1, 2025 |
| Website | https://peconic.com |
Current Holdings
Updated on Sep 18, 2026.
| Ticker | Name | Portfolio % | Return |
|---|---|---|---|
| PWR | Quanta Services Inc | 52.1% | +50.5% |
| DY | Dycom Industries Inc | 23.8% | -0.7% |
| MTZ | MasTec Inc | 16.2% | -30.9% |
| FCX | Freeport-McMoran Copper & Gold Inc | 5.5% | +9.1% |
| AMC | AMC Entertainment Holdings Inc | 1.6% | +4.7% |
| CNK | Cinemark Holdings Inc | 0.8% | +5.8% |
| GOOGL | Alphabet Inc Class A | 0.0% | +37.4% |
Recent activity
| Date | Action | Ticker | Weight |
|---|---|---|---|
| Aug 31, 2026 | SELL | FSLR | 1.3% → 0.0% |
| Aug 31, 2026 | BUY | AMC | 0.1% → 1.6% |
| Aug 31, 2026 | BUY | FCX | 3.2% → 5.5% |
| Aug 31, 2026 | SELL | PWR | 51.3% → 52.1% |
| Aug 31, 2026 | BUY | DY | 25.3% → 23.8% |
Investment Style Analysis
Peconic Partners LLC is widely recognized for employing a Long/Short Equity strategy. As of Sep 18, 2026, the firm oversees approximately $5.5B in assets under management (AUM). The portfolio demonstrates a clear preference for the Engineering & Construction and Copper sectors, reflecting a high-conviction approach to capital allocation.
Recent Market Moves
During the latest rebalancing period ending Aug 31, Peconic Partners LLC made a significant move by reducing the position in FSLR. This adjustment aligns with the fund's dynamic approach to risk management and capital deployment in current market conditions.
Investment Philosophy
Peconic Partners employs a highly disciplined thematic investment strategy designed to generate long-term positive returns regardless of market conditions. The firm's philosophy centers on identifying macro investment themes that transcend economic cycles while maintaining a deep fundamental understanding of companies within its investment universe. By combining macro vision with micro-level research, Peconic builds concentrated portfolios in core sectors like infrastructure and energy. The strategy utilizes a long/short equity framework, leveraging short positions and derivatives to hedge against market volatility and capture alpha through relative-value trades.
Disclaimer
The content provided on this page, including the simulated portfolio performance, holdings analysis, and AI-generated insights, is for informational and educational purposes only. It does not constitute financial advice, investment recommendations, or an offer to buy or sell any securities. All data is derived from historical SEC 13F filings and other public disclosures, which have a reporting lag. The "Simulated Performance" is a hypothetical reconstruction based on past disclosures and does not represent the actual returns of the institution. Past performance is not indicative of future results. Tritonix.ai is not affiliated with Peconic Partners LLC.
Similar Investment Style
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Frequently asked questions
How is the simulated portfolio for Peconic Partners LLC constructed?
This simulation is powered by Tritonix AI using official SEC filings. We focus on the "Best Ideas" by filtering for only the Top 20 largest holdings and rebalancing them to 100%. The simulation tracks performance starting from Oct 1, 2025. Our AI monitors for updates every Monday to capture major shifts. This concentrated approach highlights the manager's true stock-picking skill and mirrors their actual investment returns.
What is Peconic Partners LLC's largest holding?
As of the latest filing, Peconic Partners LLC's top position is Quanta Services Inc (PWR), representing 52.1% of the portfolio. This reflects a high-conviction bet by the institution.
What is Peconic Partners LLC's historical performance and risk profile?
Our simulation indicates a total return of +27.0% with a win rate of 83%. Notably, the portfolio maintains a Sharpe Ratio of 4.10, suggesting an exceptional level of risk-adjusted returns compared to the broader market.
What sectors does Peconic Partners LLC primarily invest in?
Peconic Partners LLC has a strong preference for the Engineering & Construction sector, which makes up 92.1% of their disclosed assets. The portfolio also has exposure to Copper, indicating a specific thematic focus.
Is Peconic Partners LLC's portfolio concentrated or diversified?
Peconic Partners LLC runs a highly concentrated portfolio with 7 disclosed positions. The top 3 holdings alone account for 92.1% of the total portfolio weight, suggesting a strategy that favors deep research into a few key names.
How has Peconic Partners LLC performed in 2026?
Our AI-simulated model portfolio for Peconic Partners LLC tracks a Year-to-Date (YTD) return of +19.4%. This metric helps investors gauge the institution's effectiveness in the current market environment.
Does William Harnisch manage Peconic Partners LLC directly?
Yes, William Harnisch serves as the key portfolio manager for Peconic Partners LLC, overseeing the investment strategy and final capital allocation decisions.