Large-capitalization (large-cap) stock

The stock of companies with market capitalizations typically of $10 billion or more is known as large-cap stock. Market cap is figured by multiplying the number of either the outstanding or floating shares by the current share price.

Large-cap stock is generally considered less volatile than stock in smaller companies, in part because the bigger companies may have larger reserves to carry them through economic downturns.

However, market capitalization is always in flux. Today's large-cap stock can drop out of that category if the share price plunges either in a general market downturn or as a result of internal problems.

And the opposite is true as well. Many of the country's largest companies began life as start-ups.