▁Bra cket ▁invest ment ▁banks ▁and ▁their ▁invest ment ▁man agers ▁are ▁head qu arter ed ▁in ▁New ▁York ▁and ▁are ▁also ▁important ▁participants ▁in ▁other ▁financial ▁cent ers . ▁The ▁city ▁of ▁London ▁has ▁histor ically ▁served ▁as ▁a ▁hub ▁of ▁European ▁M & A ▁activity , ▁often ▁facil it ating ▁the ▁most ▁capital ▁movement ▁and ▁corpor ate ▁rest ruct uring ▁in ▁the ▁area . ▁Meanwhile , ▁Asian ▁cities ▁are ▁receiving ▁a ▁growing ▁share ▁of ▁M & A ▁activity . ▁ ▁According ▁to ▁estimates ▁published ▁by ▁the ▁International ▁Fin an cial ▁Services ▁London , ▁for ▁the ▁de cade ▁prior ▁to ▁the ▁financial ▁crisis ▁in ▁ 2 0 0 8 , ▁M & A ▁was ▁a ▁primary ▁source ▁of ▁invest ment ▁bank ing ▁re venue , ▁often ▁account ing ▁for ▁ 4 0 % ▁of ▁such ▁re venue , ▁but ▁dropped ▁during ▁and ▁after ▁the ▁financial ▁crisis . ▁Equ ity ▁under writing ▁re venue ▁r anged ▁from ▁ 3 0 % ▁to ▁ 3 8 % ▁and ▁fixed - in come ▁under writing ▁account ed ▁for ▁the ▁remaining ▁re venue . ▁ ▁Re ven ues ▁have ▁been ▁affected ▁by ▁the ▁introduction ▁of ▁new ▁products ▁with ▁higher ▁marg ins ; ▁however , ▁these ▁innov ations ▁are ▁often ▁copied ▁quickly ▁by ▁compet ing ▁banks , ▁pushing ▁down ▁trad ing ▁marg ins . ▁For ▁example , ▁bro ker ages ▁comm issions ▁for ▁bond ▁and ▁equ ity ▁trad ing ▁is ▁a ▁comm od ity ▁business ▁but ▁struct uring ▁and ▁trad ing ▁derivatives ▁has ▁higher ▁marg ins ▁because