Before a company can go public it files an S-1 — a registration statement laying bare its finances, risks, and ownership. It’s the first time outsiders get a real look inside.

When a corporate insider buys or sells their own company’s stock, they must report it to the SEC on Form 4 within two business days — which is why insider trades show up so quickly.

Big investors disclose their holdings on Form 13F only 45 days after each quarter ends — so the "whale" positions everyone watches are always at least six weeks stale.

Every public company must file a proxy statement (Form DEF 14A) before its annual meeting. It’s where CEO pay, board elections, and shareholder votes are disclosed — the source behind CEO$.