Regarding the Alt coin prices between 2017 and 2018 is incomparable since there's a lot factors that influence the pricing of all alt coins in the market today 2018. Compare to the previous year of 2017 its a huge difference and too many issues that need to settle and because of this the people( potential Investors/old investors) are cautious to pour there money in this unstable market condition. that's why the market show us this movement and the affected most are those newly created Alt coins!