Carlyle Group CEO David M. Rubenstein

Carlyle Group CEO David M. Rubenstein

Jason Alden/Bloomberg

David M. Rubenstein, co-founder and co-chief executive officer of the Carlyle Group LP, walks past the Congress Center at the World Economic Forum (WEF) in Davos on Jan. 24, 2014. “Over the last couple of years people have gotten a lot less worried, but there are always things like black swans that come around,” Rubenstein said in an interview today. “I just wanted to make sure everybody remembers that and that we are likely to have some bumps along the road.”