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.
Market capitalization (or market cap) is a fairly common financial phrase. You may have seen stocks or mutual funds described as small-cap, mid-cap or large-cap on financial news websites. Or you may have read newspaper headlines referring to the market cap of a particular company, industry or region.