According to Forbes, ISIS tops the list with a $2 billion annual income and is the world’s richest terrorist organization – and the richest in the history of modern terrorism. 

Experts estimate that ISIS currently controls 60% of oil reserves in Syria, and was able to take by force or negotiate with the seven major oil and gas reserves in Iraq, including the country’s largest oil refinery. ISIS ultimately sells tens of thousands of barrels of oil on the black market daily, and the fossil fuel is a huge cash cow for the organization. The oil is sold at 40% to 75% less than the market price, yet the organization manages to pocket every day an estimated three million dollars for the sales.

Hamas is the second-richest terror organization, Forbes said, with about $1 billion being funneled to the terror group annually. 

Since taking over Gaza in 2007, Hamas has made the big leagues: in less than a decade, Hamas managed to turn the organization – which relies mainly on NGO funds and foreign aid – into a multilevel organization which also governs, and taxes, Gaza. And the taxes are high, according to Walla! News: all car owners are required to pay Hamas 1,400 shekel (about $366) annually for a licensing fee, and gas stations are heavily taxed. Much of Hamas’s income, however, is from foreign aid and NGOs – and may be a major factor in Israel’s security after the multibillion-dollar donations made from the UN and other countries after the summer’s war.