based on past likelihoods and actual occurrences, and current market expectations of such returns happening over such timespans given the agreed constraints. A feature of some structured products is a principal guarantee function, which offers protection of principal if held to maturity. For example, an investor invests $100, the issuer simply invests in a risk-free bond that has sufficient interest to grow to $100 after the five-year period. This bond might cost $80 today and after five years it will grow to $100. With the remaining funds, the issuer purchases the options and swaps needed to perform whatever the investment strategy calls for. See structured note. Origin Structured investments arose from the needs of companies that want to issue debt more cheaply. This could have been done by issuing a convertible bond—i.e., debt that could be converted to equity under certain circumstances. In exchange for the potential for a higher return (if the equity value would increase and the bond could be converted at a profit), investors would accept lower interest rates in the meantime. However, the worth of this tradeoff is debatable, as the movement of the company's equity value could be unpredictable. Investment banks then decided to add features to the basic convertible bond, such as increased income in exchange for limits on the convertibility of the stock, or principal protection. These extra features were all strategies investors could perform themselves using options and other derivatives, except that they were prepackaged as one product. The goal was again to give investors more reasons to accept a lower interest rate on debt in exchange for certain features. On the other hand, the goal for investment banks was to increase profit margins since the newer products with added features were harder to value, and thus harder to gauge bank profits. Interest in these investments has been growing in recent years, and high-net-worth investors now use structured products as way of portfolio diversification. Nowadays the product range is very wide, and reverse convertible securities represent the other end of the product spectrum (yield enhancement products). Structured products are also available at the mass retail level—particularly in Europe, where national post offices, and even supermarkets, sell investments on these to their customers; these are referred to as PRIIPs, “Packaged retail and insurance-based investment products”. Structured product business, as a key part of customer-driven derivatives business, has changed dramatically in recent years. Its