Treasury prices were mostly higher going into the auction for 30-year bonds and continued to rise afterward, pushing their yields lower. The yield on the benchmark 10-year note fell to 3.86% from 3.96% late Wednesday. The yield on the 30-year Treasury bond fell to 4.70% from 4.77% late Wednesday.
The yield on the three-month T-bill rose to 0.18% from 0.17%.
A weakening dollar, which can drive up prices of imported goods and commodities, has also brought worries of inflation. The dollar fell against other major currencies, while gold prices rose. Oil prices rose $1.35 to settle at $72.68 a barrel.
Oil has been rising, in part, as more investors look for a safe haven to stash money in because of the sliding value of the dollar.
Advancing issues outnumbered decliners by about 3 to 2 on the New York Stock Exchange. Volume came to 1.2 billion shares, essentially flat with Wednesday.
The Russell 2000 index of smaller companies rose 2.37, or 0.5%, to 526.08.
Overseas, Japan's Nikkei stock average rose 0.9%. Britain's FTSE 100 rose 0.6%, Germany's DAX index gained 1.1%, and France's CAC-40 gained 0.6%.