Bitcoin and Litecoin, two of the oldest coins have only had minor ups and downs in the last month. In the last 24 hours just about all of the newer coins have been hit with a drop of 30 to 55% while Bitcoin and Litecoin have dropped just over 10%. The difference is that BTC and LTC are currently being used to buy things while the newer coins have very few uses except trading. This is a problem which will eventually work its self out.
Look at what happen just over a month ago when the market cap dropped to 60 billion, it recovered to 100 again in a week. Will it do this again ? I think so !

I think it is a time to buy but be careful with where you put your money.