Illegal trading means when you trade something illegal like for example drugs.

The illegal drug trade is a global black market consisting of the cultivation, manufacture, distribution and sale of illegal controlled drugs. Most jurisdictions prohibit trade, except under license...

Drug commodities,online commodity trading,

Drugs become illegal when law makers decide to pass laws saying these drugs are illegal.

In the short term, the demand for illegal drugs is inelastic. As a result of law enforcement policies that reduce the supply of drugs tend to greatly increase the price of drugs , while reducing the quantity of drugs consumed very little. This increases the revenue to drug dealers. On a long term basis, only policies that reduce the demand for drugs create a more elastic market place for this type of illegal trade.