Japan’s government pension fund on Tuesday said it is requesting information on “illiquidity assets” such as bitcoin, as part of research into potential new investments.

The Government Pension Investment Fund (GPIF) of Japan, the world’s largest pension fund by assets under management on several different rankings, said it is looking for “basic information” on illiquid assets other than those in which it already invests.

GPIF said it currently puts funds in domestic and foreign bonds and stocks, real estate, infrastructure and private equity. It is now looking for information about other assets such as forests, farmland, gold and bitcoin and how these might be incorporated into the portfolio of pension funds.

There is no indication that GPIF will invest in bitcoin or other cryptocurrencies.

GPIF’s statement comes days after bitcoin hit an all-time high and after the world’s largest cryptocurrency has rallied more than 130% over the last year.

That rally is in part thanks to the launch of bitcoin exchange-traded funds in the U.S. this year, which has attracted billions of dollars of inflows.

Pension funds have been very cautious about stepping into cryptocurrency investments due to the latter’s volatile nature. Some have nevertheless dipped their toes, with South Korea’s pension fund — the National Pension Service — buying shares of Coinbase last year.

In Japan, the government in February proposed a law that would, if passed, allow investment funds to hold digital assets like cryptocurrencies.