Can Alpha Capture Save Fundamental Long/Short Equity? | David Stemerman CenterBook Partners

Episode Summary

Executive Summary: David Stemmerman argues that long-short equity is not dead; rather, allocators are misreading manager skill because alpha is masked by beta and factor exposure. Centerbook Partners aims to solve this by “alpha capture” and systematic portfolio construction—partnering with skilled fundamental managers, protecting their IP and execution, and delivering alpha in allocator-friendly formats like market-neutral and active extension strategies.

Main Topics: The case against the “death” of long-short equity (Priority: 5/5): Stemmerman rejects the notion that bottom-up stock pickers lack skill, arguing that many managers still generate strong alpha but struggle to raise capital because their return streams are obscured by market and factor effects. Why directional long-short strategies are under pressure (Priority: 5/5): He explains that post-2008 and especially after 2022, allocators increasingly prefer uncorrelated, market-neutral, and factor-neutral strategies, making it harder for directional long-short managers to attract assets. Centerbook’s alpha capture model (Priority: 5/5): Centerbook aggregates signals from independent managers and constructs systematic portfolios that seek to capture alpha while managing risk, timing, sizing, and market impact better than managers can do alone. Responsible use of manager data and IP protection (Priority: 4/5): A major theme is the ethical framework: Centerbook says it avoids trading on top of contributors, measures market impact, reimburses funds for harm, and provides transparency so managers can participate without fear of adverse execution. Alpha Theory, position sizing, and centaur-style collaboration (Priority: 4/5): Stemmerman describes combining human stock-picking skill with machine optimization—using price targets, scenarios, and risk rules to improve position sizing, portfolio construction, and trading efficiency. Single-manager active extension as the next growth phase (Priority: 5/5): Beyond multi-manager alpha capture, Centerbook sees a future in working with single managers—especially long-only or long-short PMs—to create 130-30 or active-extension products with higher information ratios. Business model and industry implications (Priority: 4/5): Centerbook pays contributors, shares performance economics, and offers analytics/consulting to improve their own funds, positioning itself as a partner rather than a platform or pod-shop replacement.

Key Arguments: Long-short equity is not dead; the market is mispricing or misreading manager skill because alpha is embedded in broader return streams that include beta and factors. Directional long-short managers often have durable stock-picking skill, but allocators only see headline returns and therefore miss idiosyncratic alpha. Centerbook’s risk model can separate alpha from beta/factor effects and identify managers with persistent skill and long-term horizons. Alpha capture can be done responsibly if the platform avoids harmful replication trading, measures market impact, and compensates contributors for any negative impact. Managers are often better at identifying ideas than sizing and timing them; systematic optimization can improve portfolio construction without replacing human judgment. The next major opportunity is single-manager alpha capture and active extension, which can combine alpha generation with index-aware risk management to improve information ratio. The model benefits allocators, managers, and even prime brokers because it can revive demand for long/short exposures, borrow, and market activity.

Data Points: Centerbook partner manager count: Over 35 - Current number of managers contributing to Centerbook, with a target to reach 40-50 and eventually 100+. Target future manager count: 40-50 near term; 100+ over time - Stemmerman’s growth expectations for the platform. Stocks in portfolio: Over 1,000 - Number of stocks represented across manager contributions. Geographic coverage: 25 countries - Centerbook’s current portfolio footprint. Long-only assets under management: $28 trillion - Goldman Sachs data cited by Stemmerman to show the scale of traditional long-only capital. Hedge fund long-only assets under management: Just under $600 billion - Comparison point used to show how much smaller the hedge-fund long-only segment is. Traditional long-only performance: No excess return - Stemmerman references Goldman data showing traditional long-only trailed the index over five years through 2024. Hedge fund long-only outperformance: 200-300 bps - Goldman data cited to show hedge-fund long-only strategies outperformed the index by this range. Active extension outperformance: Mid-single digits - Goldman data cited for 130-30/active-extension strategies. Alpha Theory model portfolio benefit: ~400 bps higher returns - Stemmerman says Alpha Theory clients on average generated about 400 basis points more than managers’ own portfolios. Typical fee example at Kanatus: 1% management fee, 20% over the index - Stemmerman’s prior fund structure for a long-only version of a long-short hedge fund. Information ratio threshold: 0.5 good, 0.75 excellent, >1 rarefied - Stemmerman explains allocator performance metrics for beta-one strategies. Sharpe ratio threshold: >1 good, >1.5 extraordinary - Comparison used to explain the appeal of superior risk-adjusted returns.

Pivotal Quotes: "The death of long-short equity is much exaggerated." — David Stemmerman: Opening framing of his view that fundamental stock-picking skill remains alive despite industry skepticism. "If you could invest solely in that bottom-up stock picking skill, which risk model would identify as idiosyncratic returns, it’s a wonderful return stream." — David Stemmerman: Explaining why alpha exists but is hard for allocators to isolate from beta and factor exposures. "What is the next leg of that story is this single manager alpha capture and single manager active extension." — David Stemmerman: Describing the firm’s forward-looking thesis beyond multi-manager alpha capture.

Implications: The interview suggests long/short investing may re-emerge through systematic partnerships that preserve manager independence while improving risk, sizing, and execution. If adopted broadly, alpha capture and active extension could revitalize fundamental stock picking and create new institutional products.