Europe’s riskiest corporate debt has rallied to pre-crisis levels, mirroring gains in US speculative-grade bonds, as investors seeking better returns pour money into a market that has seen a dearth of new bond sales.

The spread, or extra yield above government bonds that investors demand to own junk bonds, has returned toward levels seen before the selloff in March on both sides of the Atlantic. In Europe, the spread tightened to 4.69 percentage points, the lowest since March 6, as measured by ICE Indices. In the US, the spread has narrowed to 5.51 points.