A recent survey by Worthworm found that 46% of American angel investors regretted making an investment this year, according to a report published by VentureBeat today.

Angel investors account for around USD20 billion of investment into 60,000 firms every year. Worthworm studied the attitudes and outlooks of angel investors in America to find out their investment preferences, said the report.

The survey shared that the top reasons for angel investors' regret was overly optimistic financial projection, unrealistic pre-money valuations, incompatibility between startup management and investor, and wrong strategies. Of the respondents, 49% said the most important factors in a funding proposal is sustainable competitive advantage and relevant experience of the cofounders, the report explained.

VentureBeat said: "Angel investments are on the rise, but they are still highly risky. The odds of a positive return are less than 50 percent, and angels are often motivated by factors other than money."

Worthworm utilizes analytics to figure out pre-money startup valuations. The firm's tools are designed to assist entrepreneurs and angel investors in making their pitch and negotiations.