Market Stress Snarls Treasury Trading

The markets for the world’s safest and most liquid assets, the government bonds issued by the U.S. and other rich countries, are coming under immense stress on Wednesday following a week of worries about the health of global banks. 

Liquidity, the capacity to trade quickly at quoted prices, has fallen sharply in two of the keystone markets, those for U.S. Treasurys and German bunds, traders said. Difficulties in trading are now spreading to many other markets, including those for derivatives that firms and traders use to lock in prices and hedge...