China's foreign exchange reserves topped US$1.2 trillion at the end of March, adding to what was already the world's largest reserve of foreign currency, the South China Morning Post reported. The country added US$135.7 billion in the first quarter, pushing its holdings up by 12.7% from the end of last year and 37.36% year-on-year, according to figures from the People's Bank of China. The boost was driven by continuous increases in foreign direct investment, which jumped 11.6% to US$15.9 billion in the first quarter, about a quarter of last year's total of US$63 bilion. The hike is far more than economists expected, the Wall Street Journal reported. The increase shows more money is flowing into China than out of it.