The Bank of Japan (BOJ) had maintained low interest rates since 1999. In order to fight domestic deflation, the central bank of the third-largest economy in the world adopted quantitative easing for the first time in 2001, purchasing government bonds and later asset-backed securities and equities.

Since 2010 BOJ has been expanding its purchase programme on several occasions reaching the current buying of 80 trillion Yen per year - an amount that is about 16% of Japan's gross domestic product.