TOKYO, Oct. 23 (Kyodo) - The U.S. dollar rose to a two-month high against the yen in Tokyo on Tuesday morning on growing optimism about the U.S. economy. At midday, the dollar traded at 122.47-49 yen compared to Monday's 5 p.m. quotes of 122.40-50 yen in New York and 121.58-60 yen in Tokyo. The U.S. currency climbed to the 122-level in Tokyo for the first time since mid-August. It moved between 122.30 yen and 122.59 yen during the morning. The dollar traded at the 122 yen level, continuing the levels in New York the previous day on buying of the U.S. currency spurred by the climb in New York stock prices. "The U.S. economic performance will be bad over the short term, with sales during the Christmas season probably suffering, but there are hopes that a recovery will be seen in the future, helped by the series of U.S. interest rate cuts," said Shogo Nagaya, foreign exchange manager at Nomura Trust and Banking Co. At the same time, Nagaya noted that the optimism about the U.S. economy is cautious. "We know it is too early yet to become really hopeful. If the anthrax scare worsens or we see more terrorist acts, the dollar will come under downward pressure," he said. For the time being, however, players will try to take the dollar higher, driven partly by the need to adjust dollar-short positions, Nagaya said. Dealers also cited an article Tuesday in the Nihon Keizai Shimbun that said Japanese life insurers and institutional investors are boosting investment in U.S. bonds as a factor contributing to the dollar-buying sentiment. Another dollar-boosting newspaper article in the Financial Times said Toyota Motor Corp., Japan's largest automaker, will switch more of its cash reserves from yen to the dollar and euro.