GBP/JPY is in downtrend channel. The red upper line of the channel goes through two minor tops and is not very important or reliable. We can draw a line through any two points and we do not know whether this line means anything. So if price crosses above this line, the signal that occurs will not be very reliable.
Green lower line of the channel is much more interesting. First it goes through six bottoms, so it’s importance and reliability is much bigger than in the case of the upper line. Besides breakouts in direction of trend seem more reliable than breakouts against it. Considering this, crossing below the green line would be strong bearish signal, that can be used to buy a put option.