Primary vs. Secondary Sources
The difference between the original record of what a company said and did and other people's accounts of it, what each is good for, and how to trace any claim back to its source.
The short version
A primary source is the original record: a company's SEC filings, its earnings releases, a court document, official statistics. A secondary source is someone else's account of it: news stories, analyst reports, financial websites, social media posts, AI summaries. Secondary sources are fast and useful for ideas and context, but they can be wrong, out of date, or slanted. Before relying on any important number or claim, trace it back to the primary source and check the period and definition.
By the end of this lesson, you'll be able to
- Tell primary sources from secondary sources
- Explain what each kind of source is good for and where it can go wrong
- Trace a claim back to its primary source and check it
Why this matters
Most of what people read about companies is several steps removed from the original. A filing becomes a press story, the story becomes a social media post, and the post becomes a screenshot. Each step can drop context or add a slant. Knowing which sources are the original record, and checking important claims against them, protects you from building a view on a mistake.
Two kinds of sources
| Primary sources | Secondary sources | |
|---|---|---|
| What they are | The original record | Someone's account or interpretation of the record |
| Examples | SEC filings, earnings releases and call recordings, proxy statements, court records, official statistics | News articles, analyst reports, financial data websites, blogs, social media, AI summaries |
| Good for | Exact numbers, definitions, and what the company actually said | Finding ideas, quick context, and other viewpoints |
| Watch out for | Length, jargon, and management's own framing | Errors, missing context, outdated numbers, and conflicts of interest |
Primary sources aren't neutral. A company's annual report is written by the company, and management chooses how to describe its own results. But the financial statements in it follow accounting rules and are audited, and the whole document is public and on the record.1 That's a much firmer footing than someone's summary of it.
The rest of this lesson is for members
Still to come in this lesson: Financial data websites, the key takeaways, and 2 quiz questions with explanations.
Membership opens every lesson in the curriculum, the capstone projects, the interactive tools, and the members-only channels in the Hyperion Entities Discord. The first lesson of every module stays free.
Go deeper
- Reading a Real 10-K, Section by Section coming soonResearch Workshop (depth track)
- Keeping a Research Journal coming soonResearch Workshop (depth track)
Learn more
- How to Read a 10-K/10-QInvestor.gov, U.S. Securities and Exchange Commission
Notes and sources
- U.S. Securities and Exchange Commission, Office of Investor Education and Advocacy. Investor Bulletin: How to Read a 10-K. Checked 2026-10-11. Back to text
- Investor.gov, U.S. Securities and Exchange Commission. Using EDGAR to Research Investments. Checked 2026-10-01.