TOKYO -- Mutual fund assets in Japan have topped the 100 trillion yen ($806 billion) mark for the first time, buoyed by an influx of money from retail investors taking advantage of a tax-free individual savings account program.

The balance of assets held in publicly offered investment trusts came to 102.45 trillion yen at the end of May, up 3.29 trillion yen from a month earlier, according to data released Thursday by the Investment Trusts Association, Japan. The balance climbed to an all-time high in each of the past 12 months.

The figure jumped about 20 trillion yen, or 25%, from a year earlier and shot up about 41 trillion yen, or 68%, since the ongoing stock market rally that began in late November 2012 on hopes that Abenomics could lift Japan's economy out of a long-running rut.

Investing in foreign bonds and real estate investment trusts helped major mutual funds boost assets.

Assets held in exchange-traded funds -- a financial instrument the Bank of Japan purchases as part of its monetary easing measures -- also rose, more than doubling in two years to more than 14 trillion yen.

Many individuals bought mutual funds though Japan's NISA individual savings account program, introduced in January 2014, and through wrap accounts, in which investors entrust the management of their portfolios to brokerages. Mutual fund purchases tied to the NISA program had grown to 3 trillion yen through March. The balance of wrap accounts stands at about 4 trillion yen, tripling in a year.

Of the 41 trillion yen surge in mutual fund assets since the Abenomics-driven rally began more than two years ago, 24 trillion yen represents a net inflow of money -- purchases of these funds minus cancellations and redemptions -- and 17 trillion yen is the result of higher investment returns stemming from stock price gains and the weak yen.

(Nikkei)