CLS is good at preventing mishaps in the foreign-exchange market. The trouble is, it handles only 18 major currencies. That means it misses big chunks of trades where emerging-market currencies are swapped against the dollar or the euro. Overall, the protection offered by payment-versus-payment has begun to fray: from 50% in 2013, coverage fell to 40% in 2019, according to the Bank for International Settlements. After removing claims that institutions net bilaterally, $9 trillion of daily obligations are at higher risk of accidents and mistakes. Therein lies a big opportunity for blockchain tokens to prove their utility.