It looks so easy from the outside. An entrepreneur with a hot technology and venture-capital funding becomes a billionaire in his 20s.

But now there is evidence that venture-backed start-ups fail at far higher numbers than the rate the industry usually cites.

About three-quarters of venture-backed firms in the U.S. don’t return investors’ capital, according to recent research by Shikhar Ghosh, a senior lecturer at Harvard Business School.

via The Venture Capital Secret: 3 Out of 4 Start-Ups Fail – WSJ.com.