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Zweig-DiMenna Associates, Inc.
Joseph DiMenna · Hedge Fund · Long/Short Equity
Zweig-DiMenna Associates, Inc. is a New York-based investment management firm co-founded in 1984 by legendary investor Dr. Martin Zweig and Joseph DiMenna. As one of the longest-running hedge funds in the industry, the firm focuses on absolute return investing primarily through a fundamental long/short equity approach. The firm integrates deep bottom-up fundamental analysis of individual companies with a top-down macroeconomic perspective to navigate various market cycles. Over its four-decade history, Zweig-DiMenna has been recognized for its disciplined risk management and its ability to adapt to evolving financial landscapes. It caters primarily to pooled investment vehicles and managed accounts, maintaining a focus on growth-oriented capital appreciation while seeking to provide a cushion against market volatility.
Simulated Performance
| Metric | Value |
|---|---|
| Total return | +69.5% |
| YTD return | +49.9% |
| Sharpe ratio | 3.65 |
| Win rate | 54% |
| AUM | $0.7B |
| Inception | Oct 1, 2025 |
| Updated | Aug 20, 2026 |
Institution Status
| Field | Value |
|---|---|
| AUM | $0.7B |
| Turnover | Low (<15%) |
| Avg holding | 18 Months |
| Inception | Oct 1, 2025 |
| Website | http://www.zweig-dimenna.com/ |
Current Holdings
Updated on Aug 20, 2026.
| Ticker | Name | Portfolio % | Return |
|---|---|---|---|
| AMZN | Amazon.com Inc | 13.0% | +8.8% |
| SNDK | Sandisk Corp | 6.9% | +58.8% |
| WGS | GeneDx Holdings Corp. | 6.7% | +23.2% |
| MU | Micron Technology Inc | 6.5% | +0.3% |
| APP | Applovin Corp | 6.1% | -34.6% |
| AMAT | Applied Materials Inc | 5.8% | -12.1% |
| COHR | Coherent Inc | 5.5% | -19.2% |
| CRWD | Crowdstrike Holdings Inc | 5.1% | +7.1% |
| LRCX | Lam Research Corp | 5.0% | -14.7% |
| TSM | Taiwan Semiconductor Manufacturing | 4.9% | +33.7% |
| LITE | Lumentum Holdings Inc | 4.6% | +84.0% |
| AVGO | Broadcom Inc | 4.1% | +2.9% |
| NVDA | NVIDIA Corporation | 4.0% | +10.5% |
| VRT | Vertiv Holdings Co | 3.8% | +7.9% |
| META | Meta Platforms Inc. | 3.6% | -5.2% |
| V | Visa Inc. Class A | 3.4% | +11.3% |
| NTRA | Natera Inc | 3.0% | +19.6% |
| AMD | Advanced Micro Devices Inc | 2.8% | -13.3% |
| DAL | Delta Air Lines Inc | 2.7% | -12.0% |
| GOOGL | Alphabet Inc Class A | 2.7% | -3.5% |
Recent activity
| Date | Action | Ticker | Weight |
|---|---|---|---|
| Aug 17, 2026 | SELL | AMD | 2.8% → 2.8% |
| Aug 17, 2026 | SELL | LRCX | 5.0% → 5.0% |
| Aug 17, 2026 | BUY | META | 3.6% → 3.6% |
| Aug 17, 2026 | BUY | TSM | 4.9% → 4.9% |
| Aug 17, 2026 | BUY | NVDA | 4.0% → 4.0% |
Investment Style Analysis
Zweig-DiMenna Associates, Inc. is widely recognized for employing a Long/Short Equity strategy. As of Aug 20, 2026, the firm oversees approximately $0.7B in assets under management (AUM). The portfolio demonstrates a clear preference for the Semiconductors and Internet Retail sectors, reflecting a high-conviction approach to capital allocation.
Recent Market Moves
During the latest rebalancing period ending Aug 17, Zweig-DiMenna Associates, Inc. made a significant move by reducing the position in AMD. This adjustment aligns with the fund's dynamic approach to risk management and capital deployment in current market conditions.
Investment Philosophy
The firm's philosophy centers on a research-driven strategy that combines fundamental stock selection with macroeconomic and technical analysis. Zweig-DiMenna seeks to identify high-quality companies with sustainable growth drivers for long positions, while utilizing short positions to hedge exposure and generate alpha from structural or cyclical weaknesses. The investment process is flexible, allowing the portfolio to adjust gross and net exposure based on market conditions. Risk management is a core component, emphasizing liquidity, position sizing, and risk-adjusted long-term performance. By balancing bottom-up research with top-down thematic views, the firm aims to capture significant upside in equity markets while preserving capital during periods of downside volatility.
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 Zweig-DiMenna Associates, Inc..
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Based on Long/Short Equity.
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Frequently asked questions
How is the simulated portfolio for Zweig-DiMenna Associates, Inc. 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 Zweig-DiMenna Associates, Inc.'s largest holding?
As of the latest filing, Zweig-DiMenna Associates, Inc.'s top position is Amazon.com Inc (AMZN), representing 13.0% of the portfolio. This reflects a high-conviction bet by the institution.
What is Zweig-DiMenna Associates, Inc.'s historical performance and risk profile?
Our simulation indicates a total return of +69.5% with a win rate of 54%. Notably, the portfolio maintains a Sharpe Ratio of 3.65, suggesting an exceptional level of risk-adjusted returns compared to the broader market.
What sectors does Zweig-DiMenna Associates, Inc. primarily invest in?
Zweig-DiMenna Associates, Inc. has a strong preference for the Semiconductors sector, which makes up 22.3% of their disclosed assets. The portfolio also has exposure to Internet Retail, indicating a specific thematic focus.
Is Zweig-DiMenna Associates, Inc.'s portfolio concentrated or diversified?
Zweig-DiMenna Associates, Inc. runs a moderately concentrated portfolio with 20 disclosed positions. The top 3 holdings alone account for 26.5% of the total portfolio weight, suggesting a strategy that favors broader market exposure.
How has Zweig-DiMenna Associates, Inc. performed in 2026?
Our AI-simulated model portfolio for Zweig-DiMenna Associates, Inc. tracks a Year-to-Date (YTD) return of +49.9%. This metric helps investors gauge the institution's effectiveness in the current market environment.
Does Joseph DiMenna manage Zweig-DiMenna Associates, Inc. directly?
Yes, Joseph DiMenna serves as the key portfolio manager for Zweig-DiMenna Associates, Inc., overseeing the investment strategy and final capital allocation decisions.