South Korea's foreign exchange reserves rose for the seventh consecutive month in October due to an increase in investment returns and a rise in the value of non-dollar assets.

According to the Bank of Korea on Wednesday, the country's foreign currency reserves came to a record 426-point-five billion U.S. dollars as of the end of last month, up five-point-96 billion dollars from a month earlier.

It was the largest monthly gain in over two-and-a-half years, when it grew six-point-five billion dollars in January of 2018.

The country's foreign exchange reserves plunged nearly nine billion dollars in March due to market stabilization measures and the strengthening of the dollar amid the COVID-19 pandemic, but rebounded and posted growth for the following seven months. 

The central bank said the rise in October is attributed to increased returns on its foreign-currency assets and the U.S. dollar's weakness that drove up the value of other currencies when converted into the greenback. The BOK added that deposits denominated in foreign currencies also rose. 

South Korea retained its position as the world's ninth-largest holder of foreign exchange reserves at the end of September, with China topping the list, followed by Japan and Switzerland.