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.
Investors in small-cap funds may be in for a big surprise. Many portfolio managers hold heavyweight stocks like Verizon Communications, Boeing and Pfizer in funds that claim to focus almost exclusively on shares of small-capitalization companies.etween 1927 and 2012, for instance, small-cap stocks produced average annual returns of 12.9 percent, compared with a 9.9 percent gain for large companies, according to data from Vanguard.