Robert Wiltbank, PhD, a professor at Willamette University and a board member of the Angel Resource Institute, studied more than 1,200 exited investments made by angel investors over a 15-year timeframe.

His key findings:

1. The best estimate of overall angel investor returns from this data is 2.5 times their investment.
2. This 2.5x return takes a mean time of about four years.
3. In any one investment the odds of a positive return are less than 50 percent. 
4. 90 percent of all the cash returns are produced by 10 percent of the exits
5. Once investors had a portfolio of at least six investments, their median return exceeded 1X.

His summary:  Angel investing “is a “homerun” game like formal venture capital investing. Second, a portfolio of investments, even in angel investing, is a great approach. Third, whenever you’re making risky investments it is a great principle to limit your bet size and make sure that you don’t put too much of your wealth into aggressive positions.”

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