We associate the blockchain with the Bitcoin cryptocurrency. The news focuses on the currency aspect, with its soap opera of volatility and scams, forgetting the more important underlying technology, the blockchain. Major banks, financial firms, exchanges and startups are investing hundreds of millions of dollars in projects promising a revolution in securities and payment processing efficiencies. Why are they doing so and are their expectations achievable? Managers need to get beyond the hype and understand what is the blockchain, its potential uses, operation and risks. We will examine and compare the Bitcoin and Ethereum blockchains and look at current projects at JPMChase and Facebook among others.