It's like any other coin price rise or drop,at some point for some reason money is start to flow and price is rise up.I guess some people have information that something good will happen with Nano(RaiBlocks) and they start to buying that coin on exchange.When others see that price is rise more then 10 times in 10 days(from 0.4$ to 4$) pumping price is start and it is finished at 34.42$ on Jan 5.

The reasons are probably new development of wallets(desktop,mobile) and rebranding in combination with great optimism among users in time of extreme high fees that happens at that time in BTC network.Nano on the other side have no fee and it should be instant in transaction.