Market capitalisation is what the market says a company is worth in total: the price of one share multiplied by the number of shares in issue. It is the standard way to compare the size of listed companies, and it is what people mean when they call a company large-cap or small-cap.

Key takeaways

  • Market cap measures the value of equity, not the value of the whole business, it excludes debt.
  • Share price alone says nothing about size; a high price with few shares can be a small company.
  • It moves every time the share price moves.