If I had a way to make money in a "absolutely safe" "risk-free" investment that would generate a "guaranteed profit" I would not share my investment idea with anyone one. If the investment produced a "guaranteed profit" of 10% every year, I would borrow as much as I can at interest rates as high as 9% per year, and put those loan proceeds into that investment. I would be acting against my own interests to share details about my investment opportunity.