Why the Low Volatility Anomaly Persisted Through Decades of Academic Scrutiny and Rising Awareness
The anomaly persists not because investors are unaware of it, but because the forces that create it are woven into the fabric of how markets operate.
Structural barriers prevent arbitrage from correcting mispricing
Rational investors who recognize the low volatility anomaly face a fundamental problem: trading against it is costly and risky in ways that mathematical models often ignore. Short-selling high volatility stocks requires locating shares to borrow, and the most overpriced securities are frequently the hardest to locate. Borrow costs can consume a significant portion of any expected gain, and in some cases shares become unavailable entirely. Even when short positions can be established, the path to convergence is unpredictable. High volatility stocks can become more overpriced before they correct, testing the financial and psychological limits of arbitrageurs. I have studied numerous cases where well-capitalized funds abandoned contrarian positions because losses exceeded their risk tolerance before the expected reversal materialized. These implementation frictions mean that academic identification of mispricing does not automatically translate into profitable trading strategies at scale.
Institutional mandates reinforce demand for volatile equities
The investment management industry is structured in ways that perpetuate demand for high volatility stocks regardless of their expected returns. Many institutional investors operate relative to capitalization-weighted benchmarks, and significant underweights in volatile sectors create career risk for portfolio managers. A manager who avoids speculative technology or biotech holdings might outperform over a five-year horizon but could face termination after an eighteen-month period of benchmark underperformance during a speculative rally. Pension funds, endowments, and consultants reinforce this dynamic through their emphasis on tracking error and peer-relative rankings. I have interviewed dozens of institutional investors who privately acknowledge the low volatility evidence but feel unable to act on it given their mandate constraints. This creates a paradox where the investors with the most capital and sophistication are precisely those least able to exploit the anomaly they understand best.
Behavioral biases continuously renew the mispricing
Even if structural barriers were reduced, the low volatility anomaly would likely persist because the behavioral forces that create it are deeply rooted in human psychology. Each generation of investors discovers the allure of lottery-ticket stocks anew, drawn by media coverage of spectacular winners and the narrative that bold risk-taking leads to wealth. Young investors entering markets for the first time have not personally experienced the long-term underperformance of high volatility strategies and must learn those lessons through direct experience. I have observed this cycle repeat across multiple market episodes, from the dot-com era through various speculative themes that followed. The representativeness bias that causes investors to extrapolate recent winners into future dominance does not diminish with education because it operates at an intuitive level that analytical knowledge struggles to override. As long as humans make investment decisions, these biases will regenerate the conditions that sustain the anomaly.
Publication and attention have modestly weakened but not eliminated the effect
The most sophisticated question I receive concerns whether increased academic and practitioner attention has arbitraged away the low volatility premium. My analysis suggests a nuanced answer. The gross anomaly appears somewhat smaller in the most recent decade compared to earlier periods, which is consistent with partial arbitrage as more capital flows into low volatility approaches. However, the effect remains statistically and economically significant after accounting for transaction costs and liquidity constraints. I believe what has occurred is a compression rather than elimination, where the premium has narrowed to a level that reflects the remaining barriers to full arbitrage. This is actually what economic theory would predict in a world with heterogeneous investors and implementation costs. The anomaly persists at an equilibrium level where the expected profits from exploiting it just compensate sophisticated investors for the risks and costs they bear.