A spreadsheet or database showing who owns what in a company — listing all shareholders, their share counts, and ownership percentages.
A capitalization table (cap table) is the definitive record of equity ownership in a company. It lists every person or entity that holds equity — founders, investors, employees with options, advisors — along with how many shares or options they hold and what percentage of the company that represents. It shows ownership on both an issued basis (counting only shares that currently exist) and a fully diluted basis (counting all shares that would exist if all options, SAFEs, and convertible notes converted).
Investors will always ask to see a cap table before investing. Acquirers review it during due diligence. Banks sometimes require it for loans. More importantly, it's the source of truth for what you and your cofounders actually own. Cap table disputes — where different people have different mental models of the ownership split — are one of the most common and painful sources of cofounder conflict.
Keep your cap table up to date from day one. Every time you issue shares, grant options, bring in a SAFE, or issue a convertible note, the cap table needs to reflect it. For early-stage companies, a spreadsheet can work. As you approach a priced round, moving to a purpose-built tool like Carta or Pulley becomes worthwhile.