Depends on your circle of competence and how deep you are into it. For example, if you work in tech, participate in tech meetups/conferences regularly, rub shoulders with tech people all the time, you probably have some special insights into tech, and you may find it a lot easier to predict the success of tech companies much better than most. Of course, you should still do some basic research into the financials and management of the companies. There are 4 key principles that you should focus on: (1) Buy into companies that you can understand (2) Companies have honest and able management (3) Companies have a competitive advantage that's likely to last for the next 10 years (4) Calculate a sensible and attractive price (which is dependent on your desired ROI for the next 10 years). Point (4) requires some explanation: For example, if you are only looking looking at 10% returns per year and let's say you are buying the stock at $100 today, the stock price will need to reach $259.37 in ten years. Based on (1), (2) and (3), you should be able to work out some reasonable estimate for the stockprice/intrinsic value of the stock. PM me if you need more clarity.