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

Episode Summary

Executive Summary: David Stemmerman argues that long-short equity is not dead; the real problem is that allocators can’t easily see or access the alpha hidden inside directional stock-picking returns. Centerbook’s solution is alpha capture: systematically sizing, timing, and risk-managing signals from skilled managers to create cleaner, more scalable return streams, with a next step toward single-manager active extension funds.

Main Topics: Long-short equity is under pressure, not dead (Priority: 5/5): Stemmerman says bottom-up stock pickers still generate meaningful alpha, but post-2008 and especially 2022 made directional long-short strategies harder to allocate to because returns are confounded by beta and factor exposure. Alpha capture as a solution to hidden stock-picking skill (Priority: 5/5): Centerbook uses daily manager data and a risk model to isolate idiosyncratic alpha from market and style effects, then repackages it into market-neutral or active-extension portfolios for allocators. Responsible trading and IP protection (Priority: 5/5): A major theme is that alpha capture must avoid harming contributors via market impact or replication-style trading; Centerbook emphasizes transparency, reimbursement for harm, and delayed trading that preserves most alpha. Why managers join: economics, tools, and better performance (Priority: 4/5): Centerbook pays managers participation fees, shares incentive fees, and offers analytics/consulting to improve their own funds through better sizing, risk management, and portfolio construction. Allocator demand has shifted (Priority: 4/5): Pensions, sovereign wealth funds, and endowments increasingly want uncorrelated equity return streams and cleaner beta separation, making traditional directional long-short less attractive even when managers have skill. Next frontier: single-manager active extension (Priority: 5/5): Beyond multi-manager alpha capture, Centerbook sees a future in partnering with single managers to create 130/30-style active extension products with improved information ratios and institutional-scale appeal. Human + machine collaboration (Priority: 4/5): Stemmerman frames Centerbook as a 'centaur' model: humans provide variant perception and stock selection, while systematic tools optimize portfolio construction, risk, and execution.

Key Arguments: Bottom-up stock pickers still produce real alpha; the issue is not lack of skill but the difficulty allocators have separating skill from beta and factor noise. Directional long-short suffered as allocators shifted toward market-neutral and factor-neutral products after crises like 2008 and 2022. Centerbook’s daily-data risk modeling can isolate idiosyncratic returns and show that many managers have persistent stock-picking skill. Alpha capture can be done responsibly if trading avoids harming managers’ execution and if any negative impact is reimbursed. Managers often have good ideas but weak sizing/timing; Centerbook’s systematic layer improves portfolio construction and trading efficiency. Alpha Theory-style model portfolios and decision rules can raise returns materially by improving position sizing and discipline. Large allocators still want long-term fundamental alpha, especially in a more liquid, scalable, benchmark-aware format. A single-manager active extension product could deliver higher active return with lower tracking error than traditional long-only or directional long-short. The industry’s future may be hybrid: human stock selection combined with systematic portfolio/risk management. Centerbook intends to scale by adding more managers, covering more stocks and geographies, while maintaining a light footprint on underlying managers.

Data Points: Centerbook manager count: Over 35 now; target 40-50 near term; over 100 over time - Stemmerman describes current scale and growth plans for partner funds and contributor firms. Typical manager size: Hundreds of millions in AUM - Most partner managers are established and have been in business for at least a decade, though range spans from tens of millions to over $1 billion. Covered stocks: Over 1,000 stocks - The current portfolio is diversified across partner contributions and contributor firms. Geographic coverage: 25 countries - Centerbook’s strategy spans global equities. Traditional long-only AUM: $28 trillion - Goldman Sachs data cited to show the scale of long-only capital despite limited excess return. Hedge fund long-only AUM: Under $600 billion - Cited as much smaller than traditional long-only despite stronger outperformance. Long-only outperformance: 200-300 basis points - Goldman Sachs data said hedge-fund long-only strategies outperformed the index by this range over five years through 2024. Active extension outperformance: Mid-single digits - Cited for 130/30-style strategies relative to the index. Alpha Theory lift: ~400 basis points higher returns on average - Stemmerman claims client model portfolios can outperform managers’ own portfolios by this amount. Information ratio thresholds: 0.5 good, 0.75 excellent, >1 rarefied air - Used to explain why systematic active extension can be attractive to allocators. Sharpe ratio thresholds: >1 good, >1.5 extraordinary - Provided as a comparison to information ratio. Participation payment: Guaranteed payment akin to a management fee - Part of Centerbook’s compensation structure for contributor managers. Long-only fee example at Kanatus: 1% management fee and 20% over the index - Stemmerman’s prior fund structure for a long-only version of a long-short hedge fund. Launch timing for single-manager active extension: Potential debut in 2026 - Stemmerman says this next leg could move from concept to reality within months and into 2026.

Pivotal Quotes: "The death of long-short equity is much exaggerated." — David Stemmerman: Opening framing of the episode and the thesis behind Centerbook’s mission. "If you could invest surely 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 Centerbook believes alpha exists but is obscured in directional manager returns. "The next leg of that story is this single manager alpha capture and single manager active extension." — David Stemmerman: Describing the future product roadmap beyond multi-manager alpha capture.

Implications: The episode suggests a path for long-short equity to evolve rather than disappear: hide less alpha inside noisy portfolios, improve manager economics, and build scalable active-extension products that may attract large allocators and revive independent stock picking.