A glimpse at some of the world’s wealthiest entrepreneurs reveals a cornucopia of characters who have parlayed their personality traits into big bucks and success — consider the diverse and sometimes wacky personas of Donald Trump, Mark Zuckerberg and Bill Gates. Even these characters, however, display two traits that are both common and necessary among successful entrepreneurs when you boil everything down.

The web’s brightest business mavens put these two traits at the top:  An almost superhuman drive to succeed paired with an ability to take risk by the tail.

Not surprisingly, wildly successfully entrepreneurs have almost always forged their paths by relying on grit, relentlessness and hard work, says Erica Anderson, founding partner of Proteus International, in Forbes. And that drive has to come from within, she stresses.

The entrepreneurially gifted often work at their venture to the exclusion of other interests and have a hard time “turning it off,” says Steve Tobak on Inc.com. This personality type is referred to as the “70-hour-a-week obsessive, driven, hungry, and ambitious,” says Jay Goltz in the New York Times.

“Can you make it if you are just kind of ambitious? Probably, in some cases,” Goltz notes. “But most successful entrepreneurs I know paid some serious dues. They did not want to be successful, they needed to be successful.”

At the same time, they’re not afraid of risk, Anderson advises. Goetz points out the risk factor doesn’t necessarily get better along the way, so business founders need to determine early just how tolerant they are of risk.

“If you’re daunted by the idea that every day you’re basically starting from scratch … and that it’s all on you to move toward the vision — you will not be happy being an entrepreneur,” Anderson warns.

Although the fear of failure (Kakorrhaphiophobia) is among the most common phobias in the human race, it doesn’t deter diehard entrepreneurs, says Jason Bowser in a blog posted by the Minority Business Development Agency. “There’s not one successful entrepreneur out there sitting on his couch asking ‘What if?’”

As Donald Trump might point out, there may be no limit to where fearlessness and ambition might take you.