btc margin lending on poloniex currently gives about 1% per week.. which is 50% PA.
other than that.. invest it into a good alt coin.. my personal picks are coins that are not just coins.. eg. dapps, being Lisk.. and SYS , sys is still low market cap, its a decentalized market place built into the wallet. brilliant idea that i forsee many people using. at current stage its still in beta and not being used yet. cannot lose buying sys at current prices. buy sys now or buy lisk after april 11 launch.