If you believe that Cuba will do better once Castro is gone then invest in ( cuba ) a portfolio that invests in companies in Cuba and the Carribean.
It has had a slow growth over the past 3 years, nothing stellar but steady.
But maybe the momentum will start to pick up and then turmoil and power struggles will evolve.
Who knows, but as Castro passes on, the media will bring the Cuban history to the American public and investors will be actively looking to invest which will create more demand for the stock CUBA.