Investors, especially pension funds, have lots of cash set aside to buy bonds, and most of that money is still waiting to be used for purchasing debt.

Koizumi's overwhelming victory was a surprise. Further gains in stocks will fuel optimism about the economy, pushing up bond yields.

Gains of stocks give investors another reason to sell bonds.

There was index-related buying as we approach the end of the month, lifting the debt market.

The JGB market got a lift from a pullback in equity prices here, with bargain hunters emerging.