I'd say that it depends on the investment plans short-/long-term as well as the stage at which the coins/tokens were acquired. For instance if buying them at a pre-sale then you can almost assume profit once it hits the market.

I can almost hear you ask, how do you know if it will hit the market and the answer to that is based on the scalability of the project, the team and marketing power.

If buying from the market like most people are then I look at the project and its purpose, its direct competitions to work out if it adds any original value to the market and also at the investors reactions then look at some line-charts. At least these are the basics anyway.