Conservative:
Buy Bitcoin today and slowly sell off small amounts. If the current trend continues, after a month or two you'll make back your capital AND still have Bitcoin left over to hold for the longer term.
More risky:
Buy Bitcoin today and hold it all indefinitely. Just remember this rate of growth cannot happen forever, so either there's going to be a major correction as the bubble bursts, or it will stabilize at some higher value. Obviously the latter would be better.
Really risky:
Mining contract.