With 8% annual interest, we like Blockfi

They have a good management team, but they do not offer FDIC protection. They have obtained a lot of licenses though. 

Basically if they go belly up, you will lose your money. 

Blockfi charges low transaction fees for buying and selling the main crypto currencies, and you get 8.6 percent in interest on your deposit or crypto assets. 

That's a good deal for a bit of your long-term savings.