Start-up firms are raising cash by issuing new cryptocurrencies in "Initial Coin Offerings". But are these ICOs an emerging investment bubble? Economics blogger Frances Coppola and Pavlo Tanasyuk, founder of Spacebit, a "cryptocurrency for space exploration", discuss. Plus we find out what’s happening to the market for freelance online task-based work from Vili Lehdonvirta from the Oxford Internet Institute. Presented by Rory Cellan-Jones, with BBC tech reporter Chris Foxx, and special guest Alison Van Diggelen, host of the Fresh Dialogues podcast. (Image: 3D rendering of Ethereum cryptocurrency, Credit: Lightboxx/ Getty Images).