I really think COSS will be worth holding that long. Eth and BTC don't have that much room left to grow, so I feel like the smaller market cap coins with a promising future are the way to go.
COSS pays dividends based on 50% of the fees it collects on the site. If you think that Binance got to be the #1 exchange in under a year, it's a no brainer that COSS is a good long hold. They've really been putting a lot of work into making the exchange better lately. It really shows.