TOKYO: The Bank of Japan's holdings of exchange-traded funds (ETF) is likely reaping unrealised profits of around 12-13 trillion yen ($116 billion-125 billion), BOJ Governor Haruhiko Kuroda said on Wednesday.

A rough estimate shows the market value of the central bank's ETF holdings will not fall below book value unless Tokyo's Nikkei stock average slides below 21,000, Kuroda told parliament.