This was not necessarily the best investment opportunity that I have ever seen, but it was one of the highest priced and, at the same time, had very low volatility such that it was cheap to buy long-dated puts. The investment was buying puts on the Japanese Yen. One route was via Guggenheim CurrencyShares Japanese (NYSEARCA:FXY). Here are the investment idea's early results:
We are in a global currency debasement competition and Japan remains my candidate for the "winner".