1. What Is Market Capitalization?
Market capitalization — "market cap" — is the total dollar value of all a company's outstanding shares. It represents what the market thinks the entire company is worth in equity terms.
A company with 500 million shares trading at $40 has a market cap of $20 billion. This single number is the standard way investors gauge a company's size.
2. Why Market Cap Beats Share Price
A common beginner mistake is judging a company by its share price. A $500 stock is not "expensive" and a $5 stock is not "cheap" — price alone tells you nothing about size or value.
Example: A company at $10 with 10 billion shares ($100B market cap) is far larger than one at $1,000 with 10 million shares ($10B market cap). Always look at market cap, not the sticker price.
3. Large, Mid, and Small Caps
Companies are grouped into size tiers, each with different risk and growth characteristics:
- •Mega cap (over $200B): the largest, most established global companies.
- •Large cap ($10B–$200B): mature, stable, widely held blue chips.
- •Mid cap ($2B–$10B): a balance of growth potential and established operations.
- •Small cap ($300M–$2B): higher growth potential but more volatile and riskier.
- •Micro cap (under $300M): speculative, thinly traded, highest risk.
4. Why the Tier Matters
Large Caps
Lower volatility, often pay dividends, and hold up better in downturns — but slower growth. They anchor most portfolios and indexes.
Small Caps
Greater room to grow and outperform over the long run, but with sharper swings and higher failure risk. Better suited to risk-tolerant investors.
Diversifying across market-cap tiers is a core portfolio strategy, covered in our diversification guide.
5. Free Float and Weighting
Not all shares trade freely — founders and insiders often hold large blocks. Free-float market cap counts only shares available to the public, and it's what most major indexes use to weight their members.
This is why the biggest companies dominate indexes like the S&P 500: their enormous market caps give them the largest weightings, as explained in our market indexes guide.
6. Market Cap on WIT
Every stock page on WIT displays market capitalization prominently. To use it well:
- Compare companies by market cap, never by share price alone.
- Note the size tier to gauge expected volatility and growth.
- Browse the markets dashboard to see how the largest caps drive index moves.