0527 GMT - The Bank of Japan has succeeded in preventing long-term government bond yields from rising in a disorderly manner, JPMorgan says in a note. Gov. Kazuo Ueda's cautious stance over cost-push inflation and his nimble approach to additional rate increases have led to easing of concerns that the BOJ could fall behind the curve in dealing with inflation, the U.S. bank says. Commodity trading advisers and other short-term speculators have built historically large bearish positions in Japanese government bonds through futures and swaps, JPMorgan says. If long-term Japanese government bond yields and yen rates remain stable and real-money investors start buying long-term bonds, speculators could be forced to cover their short positions, the bank says.