Copy of Robert Kiyosaki's Rich Dad Poor Dad book. Source: TechGaged / Shutterstock Best-selling author and entrepreneur Robert Kiyosaki has once again challenged conventional investment wisdom, as he warned investors not to blindly trust claims that U.S. government bonds are safe. The “Rich Dad Poor Dad” author referenced Bitcoin (BTC) alongside gold and silver as he urged followers to pay attention to where capital is moving. His latest comments arrive as investors continue debating the outlook for both conventional and emerging asset classes.