It takes several steps of research before trusting a new altcoin. First I consider if its relevant to create a new coin and what they can bring to the market. Then I search up the CEO and developers of the project to see if they have experience to support their plans. And then I read carefully the whitepaper to set a potential gauge for the coin. If there is an ICO, the results are a good indicator of the future success of the company. I also assess if the route map is realistic. I graduate my investment according to the results of the first stages of the project.
In fact several investigations are need if you are going to trust on a coin and want to invest money there. i think that the most important is that you must study the ICO of such coin their white paper and their road mape. the second is that you must check the interste of the people, you need to check the volume that how high is te volume of new coin, after getting such informations you can decide that either you should trade such altcoin or not.