I midten af 2014 meddelte irakiske efterretningskilder, at de havde oplysninger fra IS's dokumenter, som afslørede, at organisationen havde aktiver til en værdi af 2 milliarder dollars<ref>{{cite web|last=Chulov|first=Martin|url=http://www.theguardian.com/world/2014/jun/15/iraq-isis-arrest-jihadists-wealth-power|title=How an arrest in Iraq revealed Isis's $2bn jihadist network|date=15. juni 2014|work=The Guardian|access-date=17. juni 2014|archive-date=16. juni 2014|archive-url=https://web.archive.org/web/20140616091317/http://www.theguardian.com/world/2014/jun/15/iraq-isis-arrest-jihadists-wealth-power|url-status=live}}</ref>, hvilket gør IS til den rigeste jihadistgruppe i verden.<ref>{{cite news|last=Moore|first=Jack|date=11. juni 2014|title=Mosul Seized: Jihadis Loot $429m from City's Central Bank to Make Isis World's Richest Terror Force|url=http://www.ibtimes.co.uk/mosul-seized-jihadis-loot-429m-citys-central-bank-make-isis-worlds-richest-terror-force-1452190|newspaper=International Business Times UK|access-date=19. juni 2014|archive-date= 1. april 2019|archive-url=https://web.archive.org/web/20190401070053/https://www.ibtimes.co.uk/mosul-seized-jihadis-loot-429m-citys-central-bank-make-isis-worlds-richest-terror-force-1452190|url-status=live}}</ref> Trefjerdedele af dette beløb skulle angiveligt stamme fra aktiver beslaglagt, efter at gruppen erobrede Mosul i juni 2014, dette inkluderer muligvis op til 429.000.000 dollars stjålet fra Mosuls centralbank sammen med yderligere millioner og en større mængde guld stjålet fra en række andre banker i Mosul.<ref name="WAPO richest">{{cite news|last=McCoy|first=Terrence|date=12. juni 2014|title=ISIS just stole $425 million, Iraqi governor says, and became the 'world's richest terrorist group'|url=http://www.washingtonpost.com/news/morning-mix/wp/2014/06/12/isis-just-stole-425-million-and-became-the-worlds-richest-terrorist-group|work=The Washington Post|access-date=18. juni 2014|archive-date=17. juni 2014|archive-url=https://web.archive.org/web/20140617162339/http://www.washingtonpost.com/news/morning-mix/wp/2014/06/12/isis-just-stole-425-million-and-became-the-worlds-richest-terrorist-group|url-status=live}}</ref><ref>{{cite news|last1=Carey|first1=Glen|last2=Haboush|first2=Mahmoud|last3=Viscusi|first3=Gregory|title=Financing Jihad: Why ISIS Is a Lot Richer Than Al-Qaeda|url=http://www.bloomberg.com/news/2014-06-26/looted-banks-fund-iraq-fighters-eyeing-wealth-al-qaeda-never-had.html|access-date=19. juli 2014|publisher=Bloomberg News|date=26. juni 2014|archive-date=14. juli 2014|archive-url=https://web.archive.org/web/20140714183941/http://www.bloomberg.com/news/2014-06-26/looted-banks-fund-iraq-fighters-eyeing-wealth-al-qaeda-never-had.html|url-status=live}}</ref> Der har været rejst tvivl om, hvorvidt ISIL var i stand til at hente et sådan beløb fra centralbanken<ref>{{cite news|title=U.S. Official Doubts ISIS Mosul Bank Heist Windfall|url=http://www.nbcnews.com/storyline/iraq-turmoil/u-s-official-doubts-isis-mosul-bank-heist-windfall-n139846|access-date=22. juli 2014|publisher=NBC News|date=24. juni 2014|archive-date= 1. april 2019|archive-url=https://web.archive.org/web/20190401122055/https://www.nbcnews.com/storyline/iraq-turmoil/u-s-official-doubts-isis-mosul-bank-heist-windfall-n139846|url-status=live}}</ref>, og om bankrøveriet overhovedet har fundet sted.<ref name="ft bank">{{cite news|last1=Daragahi|first1=Borzou|title=Biggest bank robbery that 'never happened' – $400m Isis heist|url=http://www.ft.com/cms/s/0/0378d4f4-0c28-11e4-9080-00144feabdc0.html|access-date=21. juli 2014|work=Financial Times|date=17. juli 2014|archive-date=26. august 2016|archive-url=https://web.archive.org/web/20160826115816/http://www.ft.com/cms/s/0/0378d4f4-0c28-11e4-9080-00144feabdc0.html|url-status=live}}<!--{{subscription required}}--> Accessible via Google.</ref>
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