BEIJING - The Chinese mainland's overseas portfolio investment continued to rise in the first half of the year, with Hong Kong still the prime destination, according to official data.

At the end of June, the mainland's overseas portfolio investment assets (excluding reserve assets) amounted to $518.3 billion, up from $497.7 billion at the end of 2017, according to the State Administration of Foreign Exchange.

Of the total, $308 billion were held in equities, while the remaining $210.3 billion flowed into bonds.

Nearly one-third of the total was invested in China's Hong Kong. The next largest sums were invested in the United States, followed by the Cayman Islands.

China started to publish figures on overseas portfolio investment in January 2016 after joining the Coordinated Portfolio Investment Survey conducted by the International Monetary Fund at the end of 2015.