Nothing is 100% but here is something that works regularly.
Read ForexLive.com and watch out when we make posts like this:
As I've a multitude of times, 'stability' comments from Japan are code for 'we do not want the yen to strengthen'.
Also watch for this sort of thing:
Justin pointing out that the yen was weaker but not as much as expected.
Yen dropped, see chart below and helpful red line:
