By Katya Wachtel

For Omega Advisors' Steve Einhorn, the window of sleep-able hours is narrowing.

"One needs to know whats going on around the world. I turn in around midnight so I can monitor what's going on in China and Japan," Einhorn, vice chairman at Leon Cooperman's $7billion fund, said at the Reuters Global Investment Summit last week.  "A decade ago, did I and most others focus on what's going on in China? No. Now we wait for the November manufacturing index for China to come out. The day is longer because of that. I am up around 6 in the morning; I review what has gone on overnight in Asia and in Europe. I spend an hour in front of the machine at home, going through data and news releases" before he's out the door.