A book given to historical rambling, but the Ross Ulbricht/Silk Road chapter is particularly good and insightful on what happens when you overextend an ideology to the point of monstrosity.
A short book on the collapse of Mt. Gox, based on the authors’ work over the past few years for the Daily Beast. The book badly needs an editor, but does have bits worth the read. Also, it’s cheap.
The thought “I know PHP! How hard could running an exchange be?” never goes anywhere good.