An illegal market is an economic activity carried out outside government-sanctioned channels.
Underground markets sell illegal goods and services, legitimate goods and services to avoid taxes, or both.
Examples of underground markets include the sale of illegal drugs, weapons, human trafficking and the illegal wildlife trade.
Underground markets can have a negative impact on the economy as activities are not reported and taxes are not levied on transactions.
Underground markets do provide some benefits, such as creating jobs for those who may not be able to find work in traditional markets, and providing access to medicine and health care for people who might not otherwise have access.
Black money includes all funds earned as a result of illegal activities, as well as other legitimate income that is not taken into account for tax purposes.
A boiler room is a scheme in which sellers use high-pressure selling tactics to persuade investors to buy securities, including speculative and fraudulent securities.
Channel stuffing refers to the practice of a company supplying more products to distributors and retailers through a distribution channel than end users can purchase in a reasonable amount of time.
A High Yield Investment Program (HYIP) is a fraudulent investment scheme that aims to generate extremely high returns in excess of 100% on investments.
A letter scam in Nigeria is a scheme in which a sender offers someone a commission - usually via email - for helping them transfer a large amount of money.
Racketeering is the acquisition of a business through illegal activities, the conduct of a business with illegal income, or the use of a business to commit illegal activities.
A fraudulent trader is an employee of a financial firm who engages in unauthorized, often high-risk activities that result in large losses for the firm.