Any nation running a $285 billion net annual trade surplus cannot possibly export enough of its currency to act as a reserve currency.
Every few weeks another claim that China's currency, the renminbi, is destined to become a reserve currency surfaces. Why this is fanciful is easily explained. First, we have to understand what turns a currency from merely a means of exchange to settle payments to a reserve currency.
A reserve currency is one that is held by a variety of nations as reserves in their central bank and banking system as a source of stability and to support domestic credit extended by the central bank and banking system. Gold performs the same two functions, which is why central banks also tend to hold gold as reserves.
A reserve currency must have four attributes to fulfill its functions as a source of stability and to support domestic credit extended by the institution holding the reserves:
1. It must be liquid, i.e. marketable in size and in any global market.
2. It must be stable enough to hold its value and liquidity during crises ...