Its Act 20 act 22. Basically, you can avoid paying personal income tax and capital gains by becoming a resident of Puerto Rico (I.E. living there for a documented 183 days out of the year). Also incorporating in PR and hiring at least 2 locals you will qualify you for substantial benefits as well. It's honestly one of the best places to be as an investor or anyone starting an internet based company from a tax savings and financial standpoint.