Looking for a minimalist solution I played with an idea of investing our money in experiences rather than things, which is a popular notion right now. Form of the icon is based on the letter S and is a visual representation of the flow between two things 'money to experience'. To make the design friendlier the stroke is rounded and the icon itself has a smiling element - we are more likely to be interested in an icon that reminds as of face - we are wired to see faces in everyday objects. My experience shows me it does work ;) It's a solution speaking to a wide range of users, while still keeping it minimal and modern.