The mainland topped the list of the world's most popular destinations for foreign direct investment while Hong Kong came second last year amid lacklustre global economic performance, according to the UN Conference on Trade and Development. About US$103 billion in cross-border investment - 40 per cent more than the previous year - poured into Hong Kong, while the mainland registered inflows of US$129 billion, a year-on-year increase of about 4 per cent, the institution's World Investment Report 2015 said. This compared favourably with a 16 per cent fall in global inflows during the same period, because of "fragility of the global economy, policy uncertainty for investors and elevated geopolitical risks", the report said. In terms of outflows, Hong Kong ranked second, with US$143 billion moving out of the city last year. It followed the US$337 billion in the United States and surpassed the mainland's US$116 billion. Simon Galpin, director general of government agency Invest Hong Kong, said yesterday it was "encouraging" to see the city rank second in global foreign direct investment flows. He said foreign investors used Hong Kong as a base to then invest in the rest of China and the region. But Bank of East Asia chief economist Paul Tang Sai-on questioned whether Hong Kong could sustain such fast growth.