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.
Microcap stock. The term microcap stock (also micro-cap) refers to the stock of public companies in the United States which have a market capitalization of roughly $50 million to $300 million. The shares of companies with a market capitalization of less than $50 million are typically referred to as nano-cap stocks.