A majority of all new, angel-backed companies fail completely, so if you invest in only one company, the odds are that you will LOSE ALL YOUR MONEY, not just “not make a profit”.
Several studies and mathematical simulations have shown that it takes investing the same amount of money consistently into at least 20-25 companies before your returns begin to approach the typical return of over 20% for professional, active angel investing. This means the greater the number of companies into which the angel syndicate invests, the greater the likelihood of an overall positive return. 
Angel investing (like venture capital) follows the classic J-curve. Because unsuccessful companies tend to fail early, and big exits from the successful ones tend to take a long time to develop, when you graph it on a timeline, the overall value of an angel portfolio makes a shape like the letter “J”. The value immediately begins dropping for several years as soon as you start investing, and only after a fair amount of time does it change direction and begin to be worth more than the original investment.>>> READ MORE at: