Market Cap Explained: Large-Cap, Mid-Cap, Small-Cap

What Is Market Cap?

Market Cap = Share Price × Total Shares Outstanding

It's the total value the market places on a company. Example: $50 share × 1 billion shares = $50 billion market cap.

Categories

• Large-cap: Over ~$10B. Established companies like Apple, Microsoft. Lower risk, moderate growth.
• Mid-cap: ~$2B–$10B. Growing companies. Balance of risk and opportunity.
• Small-cap: Under ~$2B. Smaller, often faster-growing but riskier. More volatility.

Why It Matters

• Risk: Small-caps tend to swing more than large-caps.
• Return potential: Small-caps have historically outperformed over long periods—but with more volatility.
• Diversification: A portfolio mixing large, mid, and small cap can capture different sources of return.

For Your Portfolio

Beginners often start with large-cap (S&P 500 or total market). Add small-cap if you want more growth potential and can stomach volatility. Index funds make it easy to get exposure to all size segments.