What Is Market Capitalization?
Market capitalization (market cap) is calculated by multiplying a company's current share price by its total number of outstanding shares. It represents the total equity value of the company as priced by the market.
Common market cap classifications:
- Mega-cap: above $200B. Most stable, deeply liquid (AAPL, MSFT, NVDA). - Large-cap: $10B - $200B. Established companies, generally liquid. - Mid-cap: $2B - $10B. Growth-oriented, moderate liquidity. - Small-cap: $300M - $2B. Higher risk and return potential, less liquid. - Micro-cap: $50M - $300M. Highly volatile, often manipulable. - Nano-cap: below $50M. Penny stocks, high fraud risk.
Market cap affects index inclusion (S&P 500 requires $14.6B+ minimum), institutional ownership (large funds can't buy small-caps), and liquidity (large positions in small-caps cause significant slippage).
The related concept of float — the number of shares actually available for public trading — matters for understanding actual trading liquidity, particularly in stocks where founders or insiders hold large blocks.
Related terms
- Liquidity — The ease with which an asset can be bought or sold without significantly affecting its price.
- Volatility — A statistical measure of how much an asset's price varies over a period.
- Fundamental Analysis — Evaluating an asset's intrinsic value based on financial and economic factors.