Japanese yen hits 150 against the U.S. dollar, weakest levels not seen since August 1990

The Japanese currency weakened against the U.S. dollar, reaching levels not seen in more than 20 years.

Next week, the Bank of Japan will hold a two day meeting. Policymakers decided not to raise the rate in order to defend against further depreciation of the currency.

The central bank promised to defend the ceiling on the 10-year government debt yields. The yield on the 20-year bond has risen in the last year.

The Bank of Japan is buying bonds. It offered to buy 100 billion of Japanese government bonds with maturities of 10 to 20 years, and another 100 billion with maturities of 5 to 10 years.

The central bank has vowed to buy an unlimited amount of bonds at a fixed rate in order to cap 10-year government debt yields at 0.25

The finance minister of Japan said the government will take steps against excess volatility.

The recent rapid and one-sided decline of the Japanese currency are not desirable. He said that they couldn't tolerate excessively volatile moves.

Richard Yetsenga said he is not that worried about the levels ofUSD/JPY.

He said on CNBC that he doesn't think we're into destabilizing currency territory yet.

He asked, "What problems has it engendered?"

The Bank of Japan decided last month to maintain low interest rates in order to support the country's lagging economy.

The intervention pushed the Japanese currency to 142 against the US dollar. The spread between the highest and lowest points has not been this wide in two years.

The dollar was worth around 159.8 against the Japanese currency in 1990.