Once upon a time, the NYSE was the world's most important exchange and judging by the commotion over its historical trading halt when it was offline for just under 4 hours, one would think it still is. Unfortunately for the NYSE and its new owners, the ICE, it isn't, and as the following market share chart from Nanex [3]shows, the NYSE whose share of the total NMS volume is shown in red, may well have stayed closed and few would even notice.
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