▁likely ▁due ▁to ▁different ▁ways ▁of ▁class ifying ▁invest ment ▁bank ing ▁re venue , ▁such ▁as ▁subtract ing ▁propriet ary ▁trad ing ▁re venue . ▁ ▁In ▁terms ▁of ▁total ▁re venue , ▁SE C ▁fil ings ▁of ▁the ▁major ▁independent ▁invest ment ▁banks ▁in ▁the ▁United ▁States ▁show ▁that ▁invest ment ▁bank ing ▁( defined ▁as ▁M & A ▁advis ory ▁services ▁and ▁security ▁under writing ) ▁made ▁up ▁only ▁about ▁ 1 5 – 2 0 % ▁of ▁total ▁re venue ▁for ▁these ▁banks ▁from ▁ 1 9 9 6 ▁to ▁ 2 0 0 6 , ▁with ▁the ▁majority ▁of ▁re venue ▁( 6 0 + % ▁in ▁some ▁years ) ▁brought ▁in ▁by ▁" tr ading " ▁which ▁includes ▁bro ker age ▁comm issions ▁and ▁propriet ary ▁trad ing ; ▁the ▁propriet ary ▁trad ing ▁is ▁estimated ▁to ▁provide ▁a ▁significant ▁portion ▁of ▁this ▁re venue . ▁ ▁The ▁United ▁States ▁generated ▁ 4 6 % ▁of ▁global ▁re venue ▁in ▁ 2 0 0 9 , ▁down ▁from ▁ 5 6 % ▁in ▁ 1 9 9 9 . ▁Europe ▁( with ▁Middle ▁East ▁and ▁Africa ) ▁generated ▁about ▁a ▁third ▁while ▁Asian ▁countries ▁generated ▁the ▁remaining ▁ 2 1 %. ▁The ▁industry ▁is ▁heavily ▁concentr ated ▁in ▁a ▁small ▁number ▁of ▁major ▁financial ▁cent ers , ▁including ▁ ▁New ▁York ▁City , ▁City ▁of ▁London , ▁Frankfurt , ▁Hong ▁Kong , ▁Singapore , ▁and ▁Tokyo . ▁The ▁majority ▁of ▁the ▁world ' s ▁largest ▁Bul ge