Using transaction level data from the inter-dealer market, we find that the price impact of one standard deviation change in FX swap order flow has increased from less than one basis point prior to 2008 to about five basis points after 2008. However, the increase in price impact is confined to periods of elevated dispersion in funding costs and over quarterends. Central bank swap lines reduce the order flow into USD, subsequently affecting the FX forward rate. In contrast, over quarter-ends and after monetary policy announcements we observe that dealers immediately adjust prices to curb order flow.

We conduct the first comprehensive study of blockchain currencies—stablecoins pegged to fiat currencies and traded on decentralized exchanges (DEXs). Using transaction-level data linked to wallet characteristics, we show that prices in these markets are generally efficient, though constrained by blockchain frictions such as gas fees and Ether volatility. DEX rates closely track traditional currency markets through arbitrage and informed trading. Traders with substantial market share and access to primary markets exert greater price impact, reflecting informational advantages. While blockchain markets may improve access for customers excluded from traditional venues, their scalability depends on addressing frictions inherent to decentralized trading.