China's foreign exchange reserves saw their biggest quarterly increase since the second quarter of 2011, with experts noting that affairs in the U.S. are complicating China's constant need to wrestle control of its currency.

The country's stash of foreign exchange reserves rose to $3.66 trillion in the three months to the end of September, from $3.5 trillion in the three-month period ending in June. This $160 billion jump signals central bank intervention aimed at slowing gains in the yuan, which is currently trading at record highs against the dollar.