This is a great time to sell those 1060 3GB cards that can't mine eth as the 6GB cards are now in tighter supply so the 3GB rose up in price a bit.  Of course the smart thing to do would have been to stop mining in Dec 2017, sell all the cards, buy ETH or your fav alt or BTC when it hit rock bottom and sell on the run up. Sure it's not as fun as mining but I think we're well past the point where the networks need to be supported through decentralization.

If you have any holdings it would make sense to take a little profit taking. Those who held entirely in 2017 missed out on a lot of opportunity. BTC and alts will most certainly crash and run up again before the next halving.