South Korea’s foreign currency reserve assets increased by nearly $2 billion on-month in September, bolstered by high returns from foreign asset investments, data showed Friday.

According to the Bank of Korea, foreign exchange reserves increased $1.8 billion on-month to $403.3 billion last month.

The figure had declined in August due to the strong dollar, but rebounded slightly last month as the central bank’s investment in foreign government bonds, mortgage-backed securities and other types of investment generated robust returns, the BOK said. The BOK didn’t elaborate further on its investments. 

Last month, the US dollar index, which monitors the greenback against a basket of major currencies, climbed 0.6 percent on-month to 99.1, prompting declines in the value of the Japanese yen and the euro by 1.3 percent and 1 percent, respectively.

Of the total assets, foreign securities accounted for 93 percent after gaining $3.5 billion to $374.5 billion over the cited period. Foreign exchange deposits accounted for 4.5 percent with $18 billion, while the nation’s special drawing rights and reserve position at the International Monetary Fund each accounted for 0.8 percent and 0.7 percent with $3.4 billion and $2.7 billion, respectively.

Its gold holdings accounted for 1.2 percent, remaining flat on-month at $4.8 billion.

Among global economies, Korea’s foreign exchange assets ranked No. 9 with $401.5 billion as of the end of August. China ranked No. 1 with $3.1 trillion and Japan was in second place with $1.3 trillion.

By Jung Min-kyung (mkjung@heraldcorp.com)