Usage patterns
通貨を発行するto issue currency
The central bank issued a new currency.
通貨の価値が上がる/下がるthe value of a currency rises/falls
The value of the yen as a currency is falling.
〈物〉を通貨に両替するto exchange something for a currency
Before the trip, I exchanged dollars for the local currency.
通貨が変動するa currency fluctuates (in value)
Recently, this country's currency has been fluctuating significantly.