Because - absent any data whatsoever and nothing but a headline about Aso and Lew having a cozy chat about FX manipulation and The BoJ's "receptiveness" to buying more ETFs - USDJPY spiked 30 pips at the open, and drum roll please, Nikkei 225 futures went 200 points vertical without blinking an eyelid.
Efficient-markets and price-discovery - don't you love it?