Cryptocurrency use is surging, but price stability – and therefore usefulness as a means of payment - has been a concern. Stablecoins were developed to address this need. How should we think about stablecoins from an analytical perspective? To us, there is a compelling analogy with currency board regimes in the flat currency world. As with currency boards, a credible, liquid backing portfolio is key for the credibility of stablecoins. The credibility of the issuer is key, which suggest a need for some future regulation.