I'm going to hold Ethereum. As a whole, it's a slow and steady rise. I may not get crazy 5x or 10x anywhere, but I'm also not going to see massive losses.

As per your point that Ethereum is the marker for altcoins, I think altcoins as a whole is a better holding for January than Bitcoin. Bitcoin still hasn't resolved its issues, and if Bitcoin surges ahead, its fees will go up again, which will lead it back down. A vicious cycle that's going to contain it, to some degree.

And as more people enter the cryptocurrency market as a whole, the more they look to diversify than holding Bitcoin as the standard-bearer.