Segment Reporting

We operate two business segments: our Trading and Clearing segment and our Data and Listings segment. This presentation is reflective of how our chief operating decision maker reviews and operates our business. Our Trading and Clearing segment comprises our transaction-based execution and clearing businesses. Our Data and Listings segment comprises our subscription-based data services and securities listings businesses. Our chief operating decision maker does not review total assets or statements of income below operating income by segments; therefore, such information is not presented below. Our two segments do not engage in intersegment transactions.

Certain segment expenses for the six months and three months ended June 30, 2017 have been reclassified to conform to our current periods' segment financial statement presentation. This reclassification increased the operating expenses for the Data and Listings segment by $33 million and $17 million for the six months and three months ended June 30, 2017, respectively, while decreasing the operating expenses for the Trading and Clearing segment by the same amounts. Financial data for our business segments is as follows for the six months and three months ended June 30, 2018 and 2017 (in millions):



	Six Months Ended June 30, 2018						Six Months Ended June 30, 2017
	Trading and Clearing Segment		Data and Listings Segment		Consolidated		Trading and Clearing Segment		Data and Listings Segment		Consolidated
Revenues:
Energy futures and options contracts	$	485	$	—	$	485	$	459	$	—	$	459
Agricultural and metals futures and options contracts	139		—		139		118		—		118
Interest rates and other financial futures and options contracts	185		—		185		172		—		172
Cash equities and equity options	827		—		827		771		—		771
OTC and other transactions	126		—		126		95		—		95
Pricing and analytics	—		516		516		—		480		480
Exchange data	—		287		287		—		280		280
Desktops and connectivity	—		243		243		—		281		281
Listings	—		220		220		—		217		217
Other revenues	108		—		108		94		—		94
Revenues	1,870		1,266		3,136		1,709		1,258		2,967
Transaction-based expenses	665		—		665		621		—		621
Revenues, less transaction-based expenses	1,205		1,266		2,471		1,088		1,258		2,346
Operating expenses	425		741		1,166		397		758		1,155
Operating income	$	780	$	525	$	1,305	$	691	$	500	$	1,191



	Three Months Ended June 30, 2018						Three Months Ended June 30, 2017
	Trading and Clearing Segment		Data and Listings Segment		Consolidated		Trading and Clearing Segment		Data and Listings Segment		Consolidated
Revenues:
Energy futures and options contracts	$	250	$	—	$	250	$	231	$	—	$	231
Agricultural and metals futures and options contracts	74		—		74		62		—		62
Interest rates and other financial futures and options contracts	94		—		94		89		—		89
Cash equities and equity options	389		—		389		390		—		390
OTC and other transactions	57		—		57		45		—		45
Pricing and analytics	—		262		262		—		242		242
Exchange data	—		144		144		—		142		142
Desktops and connectivity	—		120		120		—		137		137
Listings	—		111		111		—		109		109
Other revenues	55		—		55		49		—		49
Revenues	919		637		1,556		866		630		1,496
Transaction-based expenses	310		—		310		316		—		316
Revenues, less transaction-based expenses	609		637		1,246		550		630		1,180
Operating expenses	218		373		591		197		374		571
Operating income	$	391	$	264	$	655	$	353	$	256	$	609

Revenue from one clearing member of the Trading and Clearing segment comprised $211 million or 17% and $107 million or 17% of our Trading and Clearing revenues for the six months and three months ended June 30, 2018, respectively. Revenue from two clearing members of the Trading and Clearing segment comprised $243 million or 22% and $127 million or 23% of our Trading and Clearing revenues for the six months and three months ended June 30, 2017, respectively. Clearing members are primarily intermediaries and represent a broad range of principal trading firms. If a clearing member ceased its operations, we believe that the trading firms would continue to conduct transactions and would clear those transactions through another clearing member firm. No additional customers or clearing members accounted for more than 10% of our segment revenues or consolidated revenues for the six months and three months ended June 30, 2018 and 2017.