Market capitalization is a common way to describe the size of a publicly traded company. Investors see terms such as large-cap, mid-cap, and small-cap frequently in fund descriptions, indexes, and portfolio analysis.
What is market capitalization?
Market capitalization, often called market cap, is the total market value of a company’s outstanding shares. It is commonly calculated by multiplying the current share price by the number of shares outstanding.
Large-cap, mid-cap and small-cap
Market participants often group companies by market capitalization. The exact boundaries used for large-, mid-, and small-cap categories can vary among index providers, funds, and research firms.
Market cap is not the same as share price
A company with a lower share price can have a larger market capitalization than a company with a higher share price if it has substantially more shares outstanding.
Company size can affect portfolio behavior
Companies of different sizes may have different growth characteristics, financial resources, business maturity, and volatility. Smaller companies can offer growth potential but may also face greater business and market risks.
Use market cap as one piece of research
Market capitalization is useful for understanding company size and portfolio exposure, but it does not tell investors whether a stock is fairly valued or whether the company is financially healthy.
Educational note: This article is for general educational purposes and does not provide individualized investment, tax, or legal advice. Investing involves risk, including possible loss of principal.
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Published: September 6, 2026 Updated: September 6, 2026
Reviewed by: Allocate Yourself Editorial Team Last reviewed: 2026-09-06