The Bank of Japan's massive asset purchase program has taken it into uncharted territory, with its ballooning holdings now larger than the country's annual economic output.
Its holding reached a staggering ¥553.6 trillion ($4.9 trillion), figures released Tuesday show, compared with nominal gross domestic product of ¥552.8 trillion at the end of June.
To put the milestone into perspective, the Federal Reserve's assets are about 20 percent of U.S. GDP, while the European Central Bank's holdings are equal to about 40 percent of the eurozone economy. And while the BOJ has significantly reduced the amount of Japanese government bonds it buys, its hoard of JGBs is still expanding.