Definition of mosquito for English Language Learners. : a small flying insect that bites the skin of people and animals and sucks their blood.
What it is: Small-cap stock refers to a company with a market capitalization (calculated by taking a firm's current share price and multiplying that figure by the total number of shares outstanding) near the low end of the publicly traded spectrum.
A large-cap stock investment, defined as the stock of a company with a market capitalization of $10 billion or more, is common among both growth and value investors as a portion of an overall asset allocation.