We study how disclosure requirements for large short positions affect investor behavior and security prices. Short positions accumulate just below the applicable disclosure threshold as certain investors never disclose any of their positions. Further tests suggest that this secrecy is part of investors’ general policy of avoiding disclosure to protect their unique, profitable investment strategies against reverse engineering by competitors. No evidence supports the notion that short sellers avoid disclosure because of potential adverse effects on securities' lending fees, risk of recall, or short squeezes. Finally, the evasive behavior by short sellers in response to transparency regulations hampers price discovery.

Using the exogenous shock of the COVID-19 pandemic, we study how informed market participants incorporate fiscal space into their trading decisions. At the onset of the pandemic, short-selling activity shifted towards companies with low financial flexibility but only in countries with limited fiscal space. Among such companies, short sellers specifically targeted those that generate their revenues mainly in the domestic market. These short sellers entered their positions before the market crash, thereby generating significant abnormal returns. We find no evidence of either herding behavior prior to the market crash or a long-run performance reversal of short sellers. These findings support the notion that short sellers help to promote price efficiency in times of crisis, where governments with budgetary constraints are unable to provide sufficient stimuli to their economies.