If you are happy with slow growth then yes, it is a very safe investment and will rise this year. However, do not expect massive growth as it has already been to the moon. You should invest in cheaper coins that will reach the same price as ethereum. Take a look at LISK and NEO, both of which are competitors to ethereum and will rise rapidly this year. LISK is cheaper, but NEO is already ready with ICOs - both are better investments for 2018
This suggestion was not just good look but it is absolutely good advised. It is much better to have other option of investment because in case you got lucky of all that is your luckiest day ever. Better to pick the best option if you think there are others than the mentioned alts.