9 6 0 s , ▁however , ▁the ▁presence ▁of ▁an ▁ups c ale ▁sho pping ▁district ▁caused ▁the ▁area ' s ▁fort unes ▁to ▁increase . ▁▁ 2 1 st ▁century ▁The ▁Loop ' s ▁population ▁has ▁bo omed ▁in ▁recent ▁years . ▁ ▁Econom y ▁and ▁employ ment ▁ ▁The ▁Loop , ▁along ▁with ▁the ▁rest ▁of ▁dow nt own ▁Chicago , ▁is ▁the ▁second ▁largest ▁commercial ▁business ▁district ▁in ▁the ▁United ▁States ▁after ▁New ▁York ▁City ' s ▁Mid town ▁Manh attan . ▁Its ▁financial ▁district ▁near ▁La S alle ▁Street ▁is ▁home ▁to ▁the ▁C ME ▁Group ' s ▁Chicago ▁Board ▁of ▁Trade ▁and ▁Chicago ▁Mer c ant ile ▁Exchange . ▁ ▁A on ▁Corporation ▁maintain s ▁an ▁office ▁in ▁the ▁A on ▁Center . ▁Ch ase ▁Tower ▁houses ▁the ▁headquarters ▁of ▁Ex el on . ▁United ▁Airlines ▁has ▁its ▁headquarters ▁in ▁Will is ▁Tower , ▁having ▁moved ▁its ▁headquarters ▁to ▁Chicago ▁from ▁sub urban ▁El k ▁Gro ve ▁Township ▁in ▁early ▁ 2 0 0 7 . ▁Blue ▁Cross ▁and ▁Blue ▁Sh ield ▁Association ▁has ▁its ▁headquarters ▁in ▁the ▁Michigan ▁Pla za ▁complex . ▁Sid ley ▁Austin ▁has ▁an ▁office ▁in ▁the ▁Loop . ▁ ▁The ▁Chicago ▁Loop ▁Alliance ▁is ▁located ▁at ▁ 5 5 ▁West ▁Mon roe , ▁the ▁Ch ic ag ol and ▁Chamber ▁of ▁Com merce ▁is ▁located ▁in ▁an ▁office ▁in ▁the ▁A on ▁Center , ▁the ▁French - American ▁Chamber ▁of ▁Com merce ▁in ▁Chicago ▁has ▁an ▁office ▁in ▁ 3 5 ▁East