Low Short Interest as a Long-Only Stock Selection Signal

Summary

This strategy selects U.S. listed stocks with the lowest short-interest ratios, equally weights the first percentile of the ranked universe, and rebalances monthly. It uses the long side of the short-interest effect: a low level of shorting may indicate favorable information or a lack of informed bearish views. The document describes two explanations for the broader effect. The overvaluation hypothesis links short-sale constraints to inflated prices, while the information hypothesis treats short sellers as informed traders whose activity helps reveal company fundamentals.

The cited research reports that stocks with relatively low short interest, especially those with heavier trading, have had positive abnormal returns; other cited work links high short interest to anticipated negative news. The document also notes mixed evidence on short-sale constraints and return predictability. This is a long-only equity strategy, so it retains substantial exposure to broad market declines and is not presented as a hedge. The page supplies a portfolio rule and research context, but no detailed implementation costs or complete performance assessment for this specific strategy.

Key ideas

• The strategy ranks NYSE, AMEX, and NASDAQ stocks by short-interest ratio and holds the lowest-ranked group.
• The portfolio is equally weighted and rebalanced monthly.
• Low short interest may signal positive information or a lack of informed bearish opinion.
• Research cited links high short interest with negative future returns and low short interest with positive abnormal returns.
• The long-only portfolio remains exposed to broad equity market declines.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.