TOKYO, May 19 (Reuters) - Government bond prices dipped across all maturities on Tuesday, ahead of a 20-year debt sale, and also tracked a rise in U.S. treasuries yields as investors cheered encouraging trial results of a potential COVID-19 vaccine.
Benchmark 10-year JGB futures fell 0.21 point to 152.27, with a trading volume of 13,472 lots.
In the cash bond market, the 10-year JGB yield rose 1 basis point to minus 0.005%.
Market players refrained from taking a big position ahead of an upcoming 20-year JGBs auction for which the finance ministry will offer 900 billion yen ($8.38 billion).
The 20-year JGB yield rose 0.5 basis point to 0.345%.
Also in the superlong maturities, the 30-year JGB yield and the 40-year JGB yield gained half a basis point each to 0.475% and 0.495%, respectively.
At the short end of the market, the two-year JGB yield and the five-year yield both rose 1.5 basis points, to minus 0.165% and minus 0.125%.
Tokyo's benchmark Nikkei average added 1.5%, hitting a two-and-a-half-month high.
($1 = 107.4400 yen)
Reporting by Eimi Yamamitsu, Editing by Sherry Jacob-Phillips