The bottom line is that you want to pick carry trades that benefit not only from a positive and growing yield, but that also have the potential to appreciate in value. This is important because just as currency appreciation can increase the value of your carry trade earnings, currency depreciation can erase all of your carry trade gains – and then some. 
When scalping, traders tend to employ a leverage that starts at 50:1 and may go as high as 500:1. Knowing the effect of leveraging and the optimal leverage Forex trading ratio is vital for a successful trading strategy, as you never want to overtrade, but you always want to be able to squeeze the maximum out of potentially profitable trades. Usually a trader is advised to experiment with leverage within their strategy for a while, in order to find the most suitable one.
Leveraged trading in foreign currency or off-exchange products on margin carries significant risk and may not be suitable for all investors. We advise you to carefully consider whether trading is appropriate for you based on your personal circumstances. Forex trading involves risk. Losses can exceed deposits. We recommend that you seek independent advice and ensure you fully understand the risks involved before trading.
Between 2003 and the end of 2004, the AUD/USD currency pair offered a positive yield spread of 2.5%. Although this may seem very small, the return would become 25% with the use of 10:1 leverage. During that same time, the Australian dollar also rallied from 56 cents to close at 80 cents against the U.S. dollar, which represented a 42% appreciation in the currency pair. This means that if you were in this trade – and many hedge funds at the time were – you would have not only earned the positive yield, but you would have also seen tremendous capital gains in your underlying investment. 

Leverage simply allows traders to control larger positions with a smaller amount of actual trading funds. In the case of 50:1 leverage (or 2% margin required), for example, $1 in a trading account can control a position worth $50. As a result, leveraged trading can be a "double-edged sword" in that both potential profits as well as potential losses are magnified according to the degree of leverage used.

GBPJPY is the most confusing one in all the JPY-related pairs. It seems that very hard for it to rise up to last top on weekly chart. It closed with a weak warning bearish weekly signal last week. On this daily chart, it could drop down more after breaking through the blue short-term daily trend line. And the 3rd wave could drop down to next support which is also...