A Systematic View of How Liquidity Shapes Markets

Liquidity constraints can make fund flows a major source of returns and undermine the diversification case for alternative-market trend following.

• Illiquid assets have higher transaction costs and greater price impact, so CFM finds that properly accounting for costs can eliminate allocations to alternative markets when portfolios are scaled to institutional size.
• In its 2024 paper “Ponzi Funds,” CFM modeled large ETFs holding concentrated small-cap portfolios and found that cumulative flow-driven price impact and returns were correlated by more than 40% for one example ETF.
• The ETF’s positions were 20 times the daily dollar volume of the underlying stocks; a 1% inflow therefore required purchases equal to 20% of one day’s volume, while cumulative inflows exceeded 200%.
• The mechanism is weaker in liquid markets such as the stocks held by SPDR, where ETF flows explain less of S&P 500 performance because other factors dominate.
• CFM argues that alternative-market CTAs may have benefited from early inflows but have underperformed traditional CTAs in recent years as flows reversed and trading overwhelmed available liquidity.
• The March 2023 bond reversal after Silicon Valley Bank failed exposed the limits of diversification: both traditional and alternative CTAs suffered heavily, and risk-adjusted returns showed no evidence that alternative markets were less efficient.

Takeaway: Investors should treat liquidity and fund-flow capacity as central risks in alternative-market strategies; CFM favors liquid systematic programs for scalable, genuinely uncorrelated returns, although the analysis does not guarantee future performance.