Within the Crypto space there are groups of people who pump coins up with a ton of cash then sell them and crash the price. This usually happens with coins outside of the top 50 or top 100, and this is why it looks like RDN is a coin that is experiencing this now. Looking at the web and trying to find news on RDN there is nothing that shows any progress on the project to warrant it's 50+% surge in price for today.
RDN started the day at 47 cents and has shot up all the way to 69 cents without an ounce of good news that is meaningful. There is news that RDN's volume has increased, but there is no news related to it's Raiden Network being activated or that they managed to fix something on the Ethereum blockchain with their technology.
The Raiden Coin, RDN, seems like a great project because they are trying to help themselves and Ethereum have faster transaction times with Raiden Network. If you buy right now then you will most likely lose money on your RDN investment because there is almost no reason why the coin should be gaining in value with no news to speak of.
Only time will tell, but in the near future it has been rumored that RDN and other coins may be listed onto CoinBase, which would probably cause a huge surge in their trading volume and also their price.