Their place of the Chicago Mercantile Exchange and the Chicago Board Options Exchange as major financial players in Illinois might explain why some lawmakers wanted to give them a big tax break. A proposed bill would trim the futures exchanges' income tax rate on the bulk of their trades. This came after CME and CBOE threatened to leave the state, citing Illinois’ new corporate tax rate. However, the proposal could cost at least $60 million in potential revenue--the bill was recently put on hold. To find out more about who would benefit from the deal and whether it will pass, Eight Forty-Eight turned to reporter David Greising of the Chicago News Cooperative.