GBP/JPY is developing corrective wave B against wave A of medium term downtrend 135.11-130.63 (colored magenta in the chart). The targets of the upmove are Fibonacci retracements of 135.11-130.63 and expansions off 130.26-132.27-130.79.
Resistances:
- 132.34 = .382 retracement
- 132.43 = objective point (OP)
- 132.87 = .50 ret
- 133.40-44 = confluence area of .618 ret and expanded objective point (XOP)
If the downtrend resumes the immediate supports will be Fibonacci retracements of 122.49-139.93, and expansions off 139.93-130.26-135.11, 135.11-130.63-132.27, and 132.27-130.79-132.05.
Supports:
- 130.57 = OP
- 129.66 = XOP
- 129.50 = contracted objective point (COP)
- 129.15-13 = confluence area of .618 retracement and COP
- 127.79 = objective point (OP)

Overbought/Oversold
Assuming that the medium term trend is down it's preferable to try shorts when the Detrended Oscillator gets above the zero level (current prices) or into the overbought area (15-25 pips above the current prices).
Read more on how to apply Fibonacci studies to calculate price targets.