Ilyevsky, who spent 17 years at ISE before it was bought by Nasdaq Inc for $1.1 billion from Deutsche Boerse in 2016, will help IEX explore "potential opportunities for strategic diversification," the company said in a statement.

"I'm looking forward to using my industry experience and looking critically at markets where IEX could make a major impact by providing a fair and unconflicted choice," Ilyevsky said.

IEX operates the Investors Exchange, whose launch in 2016 followed the company's prominent appearance in Michael Lewis' 2014 nonfiction bestseller "Flash Boys: A Wall Street Revolt." (https://reut.rs/2zqqhm8)

"Flash Boys" focused on IEX's founders as they sought to create what they deemed a fairer marketplace for investors, utilizing a so-called speed bump that slowed down stock orders with the aim of preventing predatory trading practices. Other exchanges initially opposed the speed bump, though some later adopted or proposed versions of their own.

But market share growth at IEX, which unlike most of its rivals does not pay rebates to brokers that send it orders, stalled out at around 2.5 percent.

Ilyevsky, who oversaw the launch and development of two new equity derivatives markets while at ISE, will consider a number of broad areas for potential expansion by IEX, including the options market, IEX President Ronan Ryan said in a statement to Reuters.

"But we have no plans to enter that market at this point," Ryan said, referring to the options market.

IEX has also said it plans to start a corporate listings program this year, in a challenge to the Nasdaq and the New York Stock Exchange, which is owned by Intercontinental Exchange Inc.