Japan has $1.3 trillion in foreign reserves to defend the Yen
Japan holds foreign exchange reserves of roughly $1.3 trillion, second in the world only to China.
Around $1.1 trillion of that sits in foreign securities, mostly United States government debt.
The practical war chest is the foreign currency held on deposit at the central bank and at other central banks, somewhere between $150 billion and $180 billion.
Across April and May the finance ministry deployed 11.73 trillion Yen, about $73 billion, after the exchange rate breached 160.00.