Textual Classification of SEC Comment Letters
- James P. Ryans
- A version of the paper can be found here.
- Want a summary of academic papers with alpha? Check out our Academic Research Recap Category.
SEC Comment letters appear to be under-utilized by investors because these largely text-based disclosures are more difficult to access and interpret than other common disclosures. Using a naive Bayesian textual analysis procedure, I classify important SEC comment letters where the signal of importance is significantly negative abnormal returns following comment letter disclosure. Text analysis alone can identify important letters between 10% and 40% better than chance. The text analysis signal provides additional power to identify important comment letters over other signals such as insider sales and the presence of revenue recognition related comments. The incorporation of comment letter information into security prices is more pronounced for comment letters known to have been accessed by investors, using the SEC’s EDGAR download logs, providing evidence of investor inattention to important comment letters.
Should we be paying more attention to SEC Comment Letters? The authors of this paper say “Yes!”
- All SEC comment letters can be found at ftp.sec.gov.
There are a lot of findings in this paper, but Figure 1 was interesting for reasons that have nothing to do with textual analysis. The figure below shows the evolution of CAR, or cumulative abnormal returns, over a disclosure date -10 to +90 day window. We can see that information in comment letters may be slowly incorporate into prices, perhaps due to investor inattention.
- Panel (a) illustrates an unexpected positive drift with delay for all firms. This drift may be explained by the fact that the receipt of an innocuous letter is in effect a certification that the SEC has found no significant financial reporting issues.
- Panel (b) shows a negative drift of firms with greater than 2 requests in the 3 days following disclosure. It indicates that comment letters with bad news appear to be read more frequently.
Perhaps there are ways to identify firms with comment letters that have the most positive drift by eliminating those with multiple comment letter requests? Unfortunately, the author doesn’t share those results…
But he does share results after controlling for insider trading patterns:
Looks like there may be some legs to a strategy that avoids firms with comment letters and insider selling…
We’re new to comment letters, but this paper sparked some ideas.
Anyone worked with comment letters?
- The views and opinions expressed herein are those of the author and do not necessarily reflect the views of Alpha Architect, its affiliates or its employees. Our full disclosures are available here. Definitions of common statistics used in our analysis are available here (towards the bottom).
- Join thousands of other readers and subscribe to our blog.
- This site provides NO information on our value ETFs or our momentum ETFs. Please refer to this site.