Has The Bank Of Japan Started Another Round Of Central Bank Wargames?

Never pick a fight with a central bank. The only one who gets hurt is you. Unless, of course, you are another central bank. Central banks routinely intervene in the markets to influence the prices of assets, commodities and currencies. That's the way monetary policy is conducted. It's the principle behind QE. Generally, everyone co-operates. When a central bank announces that it intends to buy assets, investors queue up to sell – even though they presumably have optimized their asset portfolio...