USDJPY EW last leg down on weekly ?

Hello,
this is an idea I am looking for other opinions. If you like please comment to help me learning.

I wondered, why USDJPY was going up so far last December. Could be because of rate hike of FED, Trump factor or anything else.
From technical view in Weekly chart it seems possible for me, that it is just an upmove leg 4 that reached to upper trendline of channel and 23-Fib retracement.
So it could be beginning of a big move down (leg 5 in EW).

I am quite new to trading, so I whould appreciate comments, even short.

If I am talking rubbish, please tell me too. I am here tp learn, not to cuddle puppies :-)