GBPJPY is always on a roller coaster.
It can go up 300-500 pips in 24 hours.
Then reverse and go down 300-500 pips in down direction.
When you trade GBPJPY always keep risk as low as possible.
Daily you can make 100-200 pips easily with GBPJPY.
Just make sure that you don't risk more than 20 pips per trade.
When you trade GBPJPY, it is a good idea to check GBPUSD and USDJPY as well.
if we take a log of both sides;
By regressing log(GBPJPY) against log(GBPUSD) and log(USDJPY) you can find a linear relationship.