The term "Geppy" refers to the currency pair British Pound / Yen. This pair also known as "The Beast" or "The Dragon". The term, "Widow-maker," has also been used so please trade with caution, as the name implies.
Why would anyone call a currency pair "The Beast?? One simple word. Volatility. The GBP/JPY currency cross is one of the most volatile currency pairs that there is. If there was ever a pair out there that taught lessons in trading quickly, GBP/JPY would be it.
There are even Geppy Blogs out there fully dedicated to telling tales of it's moves.
So why is Geppy so popular? Geppy is popular for the same reason that it's dangerous. It moves with extreme volatility. Tight stops and poor risk management will kill your account in days rather than weeks with this pair. Beginners are attracted to it because of it's promised deliverance of pips. Ironically, this is definitely a pair that beginners should stay away from. What's unfortunate is that the volatility can cause a sound trading system to lose money fast because many times, the veracity of the pair is trend-less. In other words, the moves that have taken traders out were simple very volatile moves in a consolidation phase. Another pair that has a similar behavior is GBPNZD.
How can Geppy be traded?Geppy can be traded with extreme care and very good risk management. This pair has been known to average a move of 150 pips a day, on some days it moves as much as 200 pips.
Stop losses have to be set wide and lot sizes need to be small. It's worth saying again, lost sizes need to be very small. Some traders will cut their normal trade size to roughly 1/3rd or 1/4th of their normal trade size due to the volatility. The upside of this is that you can aim for higher targets.
This pair requires a lot of respect. The moves happen quickly, and they are big. If you plan on scalping, be careful not to get scalped yourself. If you're a beginner, find another pair to trade until you get the hang of forex trading. If you have trading experience, start with "toe in the water trades" and trade this pair for 2-3 weeks before moving on to bigger trades. Everyone loves the idea of collecting pips quickly, but this pair can giveth and taketh away, if you keep that in mind, you should be fine.