Long-term Treasury yields tumbled on Friday, supported by buying at the end of the month. The move comes a day after poor seven-year issuance exacerbated the decline in government bonds, with the benchmark 10-year yield rising more than 1.6 per cent at one point to a 12-month high.

The 10-year yield fell as much as 14 basis points to 1.3776 per cent today. The yield curve flattened as long-term bonds outperformed.

About 110000 10-year Treasury futures traded in the three minutes around 4 p.m., and yields fell to the day's lows. The spread on the 10-year yield fell to about 125 basis points compared with the two-year period.