(Bloomberg) -- Investors are paying a premium for bitcoin on Coinbase, one of the largest online exchanges for buying and selling the cryptocurrency..To contact the reporter on this story: Dave Liedtka in New York at dliedtka@bloomberg.net. .To contact the editors responsible for this story: Dave Liedtka at dliedtka@bloomberg.net, Jeremy Herron at jherron8@bloomberg.net. .©2017 Bloomberg L.P.