Haruhiko Kuroda

Bank of Japan Governor Haruhiko Kuroda played down concerns his unprecedented burst of monetary stimulus would create asset-price bubbles even as it delivered an immediate pay-off in global markets, with government bond yields at a record low, the yen hitting a 3-1/2 year trough and stocks surging to multi-year highs.

The yen weakened past 97 per dollar on Friday for the first time since August 2009, a day after the BOJ vowed to inject about $1.4 trillion into the economy in less than two years in a dose of shock therapy to end two decades of deflation.