The Opposing Effects of Complexity and Information Content on Uncertainty Dynamics: Evidence from 10-K Filings.

This article examines how the complexity and information content of annual reports, specifically U.S. Securities and Exchange Commission (SEC) Form 10-K filings, affect the dynamics of investor uncertainty as measured by option-implied volatility. The study finds a hump-shaped pattern in volatility following 10-K disclosures: an initial increase in uncertainty during the first 2–4 weeks, driven by the complexity of the filings, followed by a larger decrease over the subsequent 6 weeks as investors digest the information content. Larger 10-K file sizes amplify this pattern, reflecting both greater complexity and richer information. Using textual analysis, the authors distinguish the "risk factors" section as primarily capturing complexity (increasing short-run uncertainty) and the "management discussion and analysis" (MD&A) section as reflecting information content (reducing long-run uncertainty). The findings are robust across alternative uncertainty measures and control for confounding factors, and they have implications for investor learning, asset pricing, and disclosure regulation.