Plain-English investing notes, one idea at a time — every number checked against a primary source.

Library: free primary sources for new investors

Free, official places to check what you read about investing — including everything on this site.

Free, official sources — the same ones our notes cite

Where can you check investing facts for free?

These are the primary sources this site leans on most. They are free, published by the organizations responsible for the rules or the data, and they do not try to sell you anything. When a note here cites one of them, you can open the original and read it yourself.

  • Investor.gov

    U.S. Securities and Exchange Commission

    The SEC's site for individual investors: a glossary, investor bulletins and alerts, and free calculators. Many notes on this site cite it.

  • FINRA — Investors

    Financial Industry Regulatory Authority

    Guides to investment products, fees and common scams from the self-regulatory organization for U.S. broker-dealers.

  • FINRA BrokerCheck

    Financial Industry Regulatory Authority

    A free lookup of the registration and disciplinary history of U.S. brokers and firms. Use it before you hand anyone money.

  • Investment Adviser Public Disclosure

    U.S. Securities and Exchange Commission

    Look up registered investment advisers and read their Form ADV disclosure documents.

  • EDGAR full-text search

    U.S. Securities and Exchange Commission

    Annual reports, quarterly reports, fund prospectuses and other filings made with the SEC, free to search and read. Full-text search covers electronic filings since 2001.

  • TreasuryDirect

    U.S. Department of the Treasury

    Official descriptions of Treasury bills, notes, bonds, TIPS and savings bonds, and how they are sold.

  • Consumer Price Index

    U.S. Bureau of Labor Statistics

    The official U.S. inflation measure: data, methods and questions and answers.

  • Federal Reserve — Monetary policy

    Board of Governors of the Federal Reserve System

    How the Federal Reserve sets interest rates, with FOMC statements and meeting minutes.

  • CFTC — Learn and protect

    U.S. Commodity Futures Trading Commission

    Customer advisories on crypto, forex and commodity fraud from the U.S. derivatives regulator.

  • Bitcoin: A Peer-to-Peer Electronic Cash System

    Satoshi Nakamoto (2008)

    The original nine-page design paper for bitcoin — the primary source for how it was meant to work.

How do you read a primary source quickly?

  1. Find the date or version first — rules and figures change.
  2. Read the summary or the questions-and-answers page before the full document.
  3. Look for the exact sentence that supports a claim, not just the topic.
  4. If two sources disagree, prefer the one that is responsible for the rule or the data.