Financial markets were volatile earlier in the week as sentiment over the global economic outlook swung with each new Delta headline, although the prevailing mood was improving by late Friday.
Comments from ECB officials supporting the view that there is no hurry to taper the central bank's aggressive emergency stimulus continue to support mostly peripheral bonds.
Germany's 10-year Bund yield, which is closely correlated with Treasuries, fell nearly 3 basis points to -0.234%, the lowest since May 7, falling below lows hit after Friday's US jobs data.
The deal came as a test for euro zone rates before the ECB meeting, ING said.
Though yields started the week higher, they stayed far below recent highs, as expectations of a dovish tone from the European Central Bank at its June 10 meeting continued to drive the market.
Inflation has been bond investors' key focus this year, driven higher by pent-up demand and supply constraints as economies re-open, and whether it will be transitory as central bankers argue.
Euro area yields had risen sharply earlier in the month, with Germany's 10-year yield nearing positive territory last week, driven by speculation that a stronger economic outlook driven by speedier vaccinations in the bloc could prompt the ECB to slow the PEPP purchases at its June 10 meeting.
The extent to which Weidmann would deviate from recent dovish signals by ECB policymakers was being watched particularly closely as he is among the most hawkish at the bank.