Business Segments We manage, operate and provide our products and services in four business segments: Market Services, Corporate Services, Information Services and Market Technology. See Note 1, Organization and Nature of Operations, for further discussion of our reportable segments. Our management allocates resources, assesses performance and manages these businesses as four separate segments. We evaluate the performance of our segments based on several factors, of which the primary financial measure is operating income. Results of individual businesses are presented based on our management accounting practices and structure. Our chief operating decision maker does not review total assets or statements of income below operating income by segments as key performance metrics; therefore, such information is not presented below. The following table presents certain information regarding our business segments for the three and six months ended June 30, 2020 and 2019: Market Services Corporate Services Information Services Market Technology Corporate Items Consolidated (in millions) Three Months Ended June 30, 2020 Total revenues $ 975 $ 126 $ 213 $ 84 $  $ 1,398 Transaction-based expenses (699)     (699) Revenues less transaction-based expenses 276 126 213 84  699 Operating income (loss) $ 176 $ 49 $ 132 $ 15 $ (57) $ 315 Three Months Ended June 30, 2019 Total revenues $ 665 $ 123 $ 194 $ 79 $  $ 1,061 Transaction-based expenses (438)     (438) Revenues less transaction-based expenses 227 123 194 79  623 Operating income (loss) $ 127 $ 44 $ 122 $ 8 $ (45) $ 256 Six Months Ended June 30, 2020 Total revenues $ 1,908 $ 254 $ 424 $ 165 $  $ 2,751 Transaction-based expenses (1,351)     (1,351) Revenues less transaction-based expenses 557 254 424 165  1,400 Operating income (loss) $ 354 $ 94 $ 266 $ 23 $ (147) $ 590 Six Months Ended June 30, 2019 Total revenues $ 1,304 $ 243 $ 387 $ 156 $ 10 $ 2,100 Transaction-based expenses (843)     (843) Revenues less transaction-based expenses 461 243 387 156 10 1,257 Operating income (loss) $ 263 $ 87 $ 246 $ 15 $ (80) $ 531 Certain amounts are allocated to corporate items in our management reports as we believe they do not contribute to a meaningful evaluation of a particular segment's ongoing operating performance. These items, which are shown in the table below, include the following: Amortization expense of acquired intangible assets: We amortize intangible assets acquired in connection with various acquisitions. Intangible asset amortization expense can vary from period to period due to episodic acquisitions completed, rather than from our ongoing business operations. As such, if intangible asset amortization is included in performance measures, it is more difficult to assess the day-to-day operating performance of the segments, and the relative operating performance of the segments between periods. Management does not consider intangible asset amortization expense for the purpose of evaluating the performance of our segments or their managers or when making decisions to allocate resources. Therefore, we believe performance measures excluding intangible asset amortization expense provide management with a useful representation of our segments' ongoing activity in each period. Merger and strategic initiatives expense: We have pursued various strategic initiatives and completed acquisitions and divestitures in recent years that have resulted in expenses which would not have otherwise been incurred. These expenses generally include integration costs, as well as legal, due diligence and other third party transaction costs. The frequency and the amount of such expenses vary significantly based on the size, timing and complexity of the transaction. Management does not consider merger and strategic initiatives expense for the purpose of evaluating the performance of our segments or their managers or when making decisions to allocate resources. Therefore, we believe performance measures excluding merger and strategic initiatives expense provide management with a useful representation of our segments' ongoing activity in each period. Restructuring charges: We initiated the transition of certain technology platforms to advance our strategic opportunities as a technology and analytics provider and continue the re-alignment of certain business areas. See Note 19, Restructuring Charges, for further discussion of our 2019 restructuring plan. We believe performance measures excluding restructuring charges provide management with a useful representation of our segments' ongoing activity in each period. 2019 divestiture: We have included in corporate items the revenues and expenses of BWise which were part of the Corporate Solutions business within our Corporate Services segment as BWise was sold in March 2019. See 2019 Divestiture, of Note 4, Acquisitions and Divestiture, for further discussion. Other significant items: We have included certain other charges or gains in corporate items, to the extent we believe they should be excluded when evaluating the ongoing operating performance of each individual segment. For the three and six months ended June 30, 2020, other significant items included a loss on extinguishment of debt and charitable contributions made to the Nasdaq Foundation, COVID-19 response and relief efforts and social justice charities which are recorded in general, administrative and other expense in our Condensed Consolidated Statements of Income. Accordingly, we do not allocate these costs for purposes of disclosing segment results because they do not contribute to a meaningful evaluation of a particular segments ongoing operating performance. * * * * * * A summary of our corporate items is as follows: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (in millions) Revenues - divested business $  $  $  $ 10 Expenses: Amortization expense of acquired intangible assets 26 26 50 51 Merger and strategic initiatives expense 4 5 10 14 Restructuring charges 13  25  Extinguishment of debt  11 36 11 Charitable donations 12  17  Expenses - divested business    8 Other 2 3 9 6 Total expenses 57 45 147 90 Operating loss $ (57) $ (45) $ (147) $ (80) For further discussion of our segments results, see Item 7. Managements Discussion and Analysis of Financial Condition and Results of Operations-Segment Operating Results.