Stablecoins promise the most conservative idea in finance: one token, one dollar, no drama. Yet the history of the category is a record of structures that fail in remarkably creative ways. Some break because reserves are opaque, some because redemption windows are political rather than mechanical, and some because an algorithm can defend a peg only until enough people decide it cannot. The illusion is not that stablecoins are useless. It is that stability is a property you can announce rather than a discipline you must continuously fund.