Riba

Riba (Arabic: ربا‎ ribā, ) means Interest. Riba is forbidden in Islamic economic jurisprudence fiqh and considered as a major sin. Simply, unjust gains in trade or business, generally through exploitation.

There are two types of riba discussed by Islamic jurists: an increase in capital without any services provided and speculation (Maisir), which is prohibited by the Qur'an, and commodity exchanges in unequal quantities, also prohibited in the Qur'an.