Aggarwal said there are only a handful of large exchanges, and consolidation is frequent among them. The NYSE merged with the European stock exchange Euronext in 2007. And the NASDAQ merged with the Swedish exchange OMX, also in 2007.
Aggarwal expects additional consolidation in the industry – for both large and small exchanges – now that the economy is recovering.
"The markets are trying to globalize and it gives the exchanges a competitive edge," said Aggarwal. "It helps them to reduce costs and compete more effectively. Exchanges have a lot of competition from other trading platforms. Hopefully those cost savings will get passed onto investors."
Matthew Jaffee contributed to this report.