Suppose you are a US fund manager who is successfully able to pool USD 1 billion. You have promised your investors that if they invest with you for exactly three years, they are guaranteed that they will not lose their invested capital (although they may not receive interest on the capital for three years). Additionally, you will give any upside profit that you make to your investors (the upside profit can be zero). Explain the strategy to create the capital-guaranteed portfolio while the portfolio still has an upside potential (Hint: think about the necessary financial instrument to create the capital-guaranteed feature in your portfolio).