Research by Uniswap Labs and Circle suggests that foreign exchange (FX) trading and settlement on public blockchains can enhance affordability, transparency, and stability for cross-border payments. By leveraging on-chain FX, businesses and consumers can benefit from reduced remittance costs, with estimates showing potential savings of $30 billion annually for unbanked and underbanked individuals. The study highlights the use of payment stablecoins like USD Coin (USDC) and Euro Coin (EUROC) on Uniswap's protocol, which has seen significant trading volumes. On-chain FX offers advantages such as atomic transactions and reduced settlement risk, promoting financial stability. The integration of decentralized identity solutions and blockchain analytics can mitigate risks of market manipulation. Moreover, tokenized cash issuers and decentralized exchange protocols are vital for ensuring secure and efficient FX transactions. Despite these benefits, challenges such as regulatory clarity and user experience remain barriers to widespread adoption, as evidenced by initiatives like Project Mariana, which explores the potential of DeFi in FX settlement.