The illegal drug trade, drug trafficking, or narcotrafficking is a global black market dedicated to the cultivation, manufacture, distribution and sale of prohibited drugs. Most jurisdictions prohibit trade, except under license, of many types of drugs through the use of drug prohibition laws. The think tank Global Financial Integrity's Transnational Crime and the Developing World report estimates the size of the global illicit drug market between US$426 and US$652 billion in 2014 alone.
https://en.wikipedia.org/wiki/Illegal_drug_trade