What's the reason for the sudden decrease in value of many altcoins?
well the whole volume of currency traded in crypto form is a microscopic fraction of the world economy. even though we have had a boom in the last year there are still lots of people who are still to be convinced that it could be the new economy of the world. i see it as we have hit a plateau of interest and more coins are being made vs people investing in them so paint is being spread thin so to speak.
there needs to be a push to go beyond bitcoin getting bitcoins for you alt coins and get more alt coins to be accepted at retailers and then retailers can will be able to use the coins to restock or invest back in the business. that is still a long way off.
threw alot into rabbit coin only to see it fall. im still a noob at his but i think it can bounce back with time and some hard work on the owners and miners.
for example if any miners are part of a legit online business try excepting rabbit for your services or goods. it can be a risk but in the end will build a reputation and could pay off huge.
you cant get something for nothing so to speak