美国财政部拍卖四个月期国债，得标利率4.220%（5月21日报4.230%），投标倍数3.36（前次为3.21）。

Group 1 - The U.S. Treasury auctioned a four-month Treasury bill with a winning yield of 4.220%, slightly down from the previous rate of 4.230% reported on May 21 [1] - The bid-to-cover ratio for this auction was 3.36, indicating strong demand, compared to the previous auction's ratio of 3.21 [1]