In my previous email, I mentioned that the data is clear: Smaller AUM correlates with higher alpha generation potential. I was asked to "share the data". Here it is.

The case for the nimble manager isn't just a theory—it is a documented mathematical premium:

1. The "Boutique Premium" (AMG 2025 Study)

The Affiliated Managers Group (AMG) recently updated their analysis of over 1,300 firms and 5,000 strategies. The results are striking:

• Annual Outperformance: Independent boutiques outperformed non-boutiques by an average of 82 basis points (0.82%) per year net of fees over a 20-year period.


• The Volatility Edge: In high-volatility regimes, that gap widened to 116 basis points, proving that nimbleness is a primary risk-management tool.


• Access the Report: The Boutique Premium - AMG Official Research (This 2023/2024 data set was the precursor to the 2025 investor updates).

2. "Persistence of the Nimble" (Bayes Business School, 2025)

A new report from Bayes Business School (formerly Cass) quantified the "organizational drag" of mega-funds. Their research shows:

• Capacity Constraints = Alpha: Smaller managers in niches like European Mid-Cap and Emerging Markets generated a premium of 0.56% to 1.00% per year specifically because they could trade where mega-funds cannot.


• Active Share: Small managers consistently maintain an Active Share of 95%+, whereas large funds often decay into "closet indexing" (approx. 75% Active Share) to avoid career risk.


• Access the Report: Persistence of the Nimble: Understanding Boutique Manager Alpha (PDF)

3. The Mathematical Reality of "Asset Bloat"

The law of diminishing returns in active management is a documented phenomenon known as Scale Diseconomies. To move beyond theory, we can look at the two definitive mathematical pillars of this research:

• The Berk & Green Equilibrium (Stanford/Wharton): This seminal model proves that as a manager demonstrates skill, capital flows in until the fund reaches its "Critical Capacity." At this tipping point, the cost of deploying new capital (market impact and liquidity constraints) exactly offsets the manager's skill. For the investor, this means that every dollar of "bloat" beyond this capacity effectively cannibalizes their alpha.


• The Pástor-Stambaugh Evidence (University of Chicago): In a comprehensive 2022/2026 update, researchers confirmed a strong negative correlation between fund size and performance. Their data shows that as a fund—or even an entire industry—grows, the "mispricings" are traded away faster than they can be replaced. Smaller managers are the only ones mathematically capable of staying "under the radar" of this industry-level alpha decay.

Summary of the Edge:

The case for the nimble manager isn't just a theory—it is a documented mathematical reality. When we talk about 'Asset Bloat,' we are referring to Scale Diseconomies.

Simply put: Large funds are often forced to become the very 'liquidity providers' that smaller, more agile managers like those we feature at Opalesque trade against to generate alpha.

You can find further analysis on this in the Opalesque archives: The Boutique Edge: Quantifying the Advantage and in the list below.

[1] Survey of the Small-firm Effect, Norges Bank Investment Management, 2012

[2] The Boutique Advantage: Overlooked Outperformance, AMG. 2019.

[3] Is there a Boutique Asset Management Premium? Evidence from the European Fund Management Industry. Journal of Asset Management, Clare, A 23(1), pp. 19-32. 2022

[4] Brooks, F.P. Jr. The Mythical Man-Month: Essays on Software Engineering. Addison-Wesley, 1975 (20th Anniversary Edition, 1995).

[5] Straub, V.J., Tsvetkova, M. & Yasseri, T. The cost of coordination can exceed the benefit of collaboration in performing complex tasks. Collective Intelligence, 2(2), 1–16 (2023). DOI: 10.1177/26339137231156912.

[6] Wu, L., Wang, D. & Evans, J.A. Large teams develop and small teams disrupt science and technology. Nature 566, 378–382 (2019).

[7] A Survey of the Small-firm Effect, Norges Bank Investment Management, 2012

[8] The case for boutiques: A survey of boutique asset managers, Bayes Business School, Clare, Andrew D. and Hristova, Dani and Stewart, Sebastian, May 29, 2025.

[9] Asset management boutiques poised for international expansion – but more support needed, Universal Investment, Sept 03, 2024.

[10] Is there a Boutique Asset Management Premium? Evidence from the European Fund Management Industry. Journal of Asset Management, Clare, A 23(1), pp. 19-32. 2022