Which document is least likely used to locate necessary financial information for comparable company analysis?

The document least likely used to locate necessary financial information for comparable company analysis is personal emails. Personal emails typically contain informal communications and are not standardized or rigorously audited documents like the others listed.

In comparable company analysis, financial analysts rely on formal and publicly available financial documents to gather relevant data. The 10-K is a comprehensive report filed by a public company that provides a detailed overview of its financial performance, including audited financial statements and management's discussion of the financial results. Press releases often announce significant company updates, providing timely information about new product launches, earnings announcements, or changes in leadership, which can be valuable for financial analysis as well. Equity research reports are typically produced by analysts, containing insights, forecasts, and detailed financial information on a company, thus serving as a robust source for comparison.

Personal emails, in contrast, do not provide the structured, verified data needed for thorough financial analysis and are more likely to contain subjective opinions or unverified information. Therefore, they are the least reliable source when conducting comparable company analysis.