U.S. Treasury prices climbed Friday, sending the longest-maturity bond yield to a 13-month low, the latest sign of how much duration-heavy government debt has rebounded this year.   The 30-year bond (30_YEAR) yield, which falls as prices rise, was down 1.5 basis points at 3.275%, edging out a recent low in May to mark its lowest since the beginning of June 2013 on a closing basis, according to Tradeweb.

The long-bond has marked strong gains this year as global buyers find yields relatively attractive after a selloff last year. Forecasts for slow global growth are expected to keep 30-year bond yields from rising sharply, many strategists contend.

The Barclays U.S. Treasury: 20+ Year index has returned 14.3% so far this year.

The 10-year note (10_YEAR) yield fell a basis point on the day to 2.466% as investors continued to react to rising geopolitical tension in Ukraine and Gaza. Treasurys had been trading lower but swung higher in morning trade.

The 5-year note (5_YEAR) yield was down half a basis point at 1.643%.

In a light economic calendar on Friday, the University of Michigan will release its consumer sentiment index at 9:55 a.m. Eastern. The leading indicators reading comes out at 10 a.m.