BOSTON: US Treasury yields ticked lower on Tuesday as a rising COVID-19 caseload raised concerns about reopening plans.

The benchmark 10-year yield was down 1.5 basis points in morning trading at 0.6693%.

Wall Street's main indexes opened lower on Tuesday following the benchmark S&P 500's longest streak of gains this year.

Treasury yields had risen on Monday, but Tuesday's early trading showed investors remain concerned about the US economic outlook, said Jim Barnes, director of fixed income for Bryn Mawr Trust.

"After of a day of risk-on it's probably not going to take much for people to be reminded that economic conditions still have a long way to go to get back to precrisis levels," Barnes said.

On Monday, Florida's greater Miami area became the latest coronavirus hot spot to roll back its reopening, ordering restaurant dining closed, as COVID-19 cases surged nationwide and the US death toll topped 130,000.

Oil prices also fell on Tuesday on concerns a surge in new virus cases will hamper a recovery in fuel demand.

Treasury investors will focus on the results of an auction of 3-year notes due in the early afternoon.

A closely watched part of the US Treasury yield curve measuring the gap between yields on two- and 10-year Treasury notes, seen as an indicator of economic expectations, was at 51 basis points, about a basis point lower than Monday's close and in line with its level since mid-June.

The two-year US Treasury yield, which typically moves in step with interest rate expectations, was unchanged at 0.1606% in morning trading.