Mining and Holding altcoin does not guarantee success. Also how will you ROI for a year if the prices of what you mined does not move at all? By the way what are the altcoins you mine that you are expecting to grow a 100% in a year? What process did you use in picking that altcoin to mine? Trading also won't insure 10% gain per month, life for the month of August - September 1 the prices only move from 560-580$ at what rate will you get the 10% gain in one month?
There's no certain criteria that we usually look at when investing in altcoins. We basically just invest and hope for the best. We look for who are the devs, the solicited amount, etc. An obvious scam coin is obvious. And to be honest, no altcoin will grow just 100% in a year but a weak altcoin. Good altcoins grows up to 1000% in such short period of time.
Trading altcoins or Bitcoins can't be controlled at all. They say it's an unpredictable job. Well, it is. If you're looking for a stable profit and expect ROI in such a short period of time, then I don't think trading is for you unless you've become knowledgeable and so skilled about it.