I've worked within the Betting space for a long time, so when I heard about SI it wasn't a tough sell in principle although I did have a lot of questions which SI were happy to answer. You see your balance grow week to week, along with a written weekly report. Unfortunately a change of circumstances meant that I needed my investment back. I requested a withdrawal by email on Sunday and had my investment with profit in my account by Monday lunchtime. As I said to them "I have been impressed by the gains, 4.4% over 9 weeks makes a very healthy 25+% per year." My 7.5k investment had increased by £330. If you're not clear on how SI make their money it's quite simple - they trade the profit with you, at 5k invested that. So, as in my case, if you give them 7.5k to bet with, they will take half the profit, that's what keeps their staff paid & motivated, so I made £330 (now £7,830), and they made £330 over those 9 weeks. si provides an interesting alternative investment with 20%+ expected annual return. I plan to put cash back in early next year.