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Understanding Market Capitalization

Learn how company size affects risk, returns, and investment strategy.

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What is Market Cap?

Market capitalization equals the total value of all outstanding shares. It is calculated by multiplying the stock price by the number of shares outstanding.

Formula: Market Cap = Stock Price x Shares Outstanding

Market Cap Categories

  • Mega-Cap - $200+ billion (Apple, Microsoft, Amazon)
  • Large-Cap - $10-200 billion (Most S&P 500 companies)
  • Mid-Cap - $2-10 billion
  • Small-Cap - $250 million - $2 billion
  • Micro-Cap - Under $250 million

Risk and Return by Size

Historically, smaller companies have higher returns but also higher volatility:

  • Large-caps - More stable, lower growth potential
  • Small-caps - More volatile, higher growth potential
  • Mid-caps - Balance of stability and growth

Portfolio Allocation

A diversified portfolio typically includes exposure across market cap sizes. Index funds make this easy to achieve with a single investment.