Robert Greifeld, CEO of Nasdaq OMX Group, said he had no regrets over the company's failed attempt to buy NYSE Euronext.
"We’ve said all along it was opportunistic," he told CNBC Wednesday. "We said let’s take our chances. We knew we had a long fight [with the Department of Justice] but figured it was worth it. It really was a brief interlude. It was six weeks from start to finish. In our business planning it really doesn’t factor."
The Nasdaq bid failed due to potential antitrust concerns by U.S. regulators.
The winning bidder for NYSE Euronext was from Germany's Deutsche Boerse.
Greifeld said Nasdaq will still make deals "but we have a very strict acquisitions discipline." A potential acquisition must be accretive to shareholders within 12 months, be "strategically significant" and provide a higher return to shareholders than a Nasdaq share buyback or a dividend policy, Greifeld said.
He said Nasdaq remains a relevant market for new companies seeking to raise capital.
"Nasdaq is a public market and it brings to bear all the advantages of being public," he said. "The 'dark' or secondary markets are exactly that. They might be fine for a limited subset of investors but they don’t meet the greater good of the market as a whole."
This year "has been a wonderful year for capital formation," he concluded.