Evangelists of Bitcoin say its strength is the distributed ledger that no one institution controls. But as it turns out, that makes it open to sabotage, a vulnerability that will prevent it from replacing real currencies. Chicago Booth's Eric Budish has spent his career thinking about market design and proposing fixes to flaws— work that has earned him the niche title of "the LeBron James of batch auctions." According to Budish, the cost of securing Bitcoin at a really large scale is too high, and that will always limit its growth.