China's trade surplus and foreign direct investment (FDI) explain only 30% of this.

ECONOMIST: Capital inflows to China

The island runs a large trade surplus, and its foreign reserves are the world's fourth largest, behind China, Japan, and Russia.

FORBES: Taiwan

Adviser Carlton Delfeld of Chartwell Global ETF Report likes Switzerland for its strong currency backed by ample gold reserves, fiscal discipline, trade surplus and very little foreign debt.

FORBES: Magazine Article

Likewise, a surplus in U.S. foreign trade would sow the seeds of a reversal in the future.

FORBES: We Need Demand, Not Protectionism

Dollars are pouring in from China's trade surplus, as well as from foreign direct investment and from speculators betting that China's currency will appreciate.

NPR: Chinese Cash Moves Could Roil Markets

The trade surplus leads to large inflows of foreign currency, which is bought up by the central bank in order to hold down the exchange rate.

ECONOMIST: The economy just grows and grows

One reason why Chinese officials have not felt the need to devalue earlier is that foreign trade has remained in balance, or, better, in surplus.

ECONOMIST: China��s currency: The final throw | The

Foreign-investment inflows are slowing, and slower export growth will shrink the trade surplus.

ECONOMIST: China��s currency

Thanks to its widening trade surplus and strong inward investment, the country has experienced heavy inflows of foreign exchange, which swell domestic liquidity.

ECONOMIST: Economics focus: A stitch in time saves nine | The

Many of China's exports are products that are made in China on contract for foreign companies, he said, so the U.S. shouldn't criticize China for running a big trade surplus.

WSJ: Tech Supply Chain Exposes Limits of Trade Metrics