Carry trade

最近股市波動的很大，其中一個重要的觀察是日圓的變動，基本上日圓升值對投資是一件壞事，因為很多投資單位是去借日圓來作投資的，一旦日圓升值，就表示要還的錢變多了，就趕快去還，而一窩蜂的去買日圓，又會造成更大加速升值，然後又影響到其他本來還在借錢的投資單位也要趕快出清投資來還錢，是一個很恐怖的連鎖反應。這是一個投資人須要瞭解的故事，carry trade。 

下面連結是wiki對carry trade的說明 
http://en.wikipedia.org/wiki/Carry_%28investment%29 

The term carry trade without further modification refers to currency carry trade: investors borrow low-yielding and lend high-yielding currencies. It tends to correlate with global financial and exchange rate stability, and retracts in use during global liquidity shortages. 

The risk of carry trades is that foreign exchange rates will change, and the investor will have to pay back now more expensive currency with less valuable currency. In theory, carry trades should not yield a predictable profit because the difference in interest rates between two countries should equal the rate at which investors expect the low-interest-rate currency to rise against the high-interest-rate one. However, carry trades weaken the target currency, because investors sell what they have borrowed, and convert it into other currencies. 

As of early 2007, it is estimated that as much as US$1 trillion may be staked on the yen carry trade. Since the late-1980's, the Bank of Japan has set Japanese interest rates at extremely low levels making it profitable to borrow Japanese yen to fund activities in other currencies. 

簡短地說，[Carry trade]就是借利率低的貨幣來投資利率高的資產，而目前全世界利率最低的貨幣就是日圓，當然就造成了[日圓套利交易]這個名詞，但值得注意的是，wiki那頁前一段有提到， 

Carry trades are not arbitrages: they make money even if nothing changes, but things may change. 

指Carry trades不是套利，中文雖然有套利這個詞，但意義有些不同，哪裡不同? 我沒辦法說的很清楚，既然如此，就來繼續看arbitrages的完整說明， 

http://en.wikipedia.org/wiki/Arbitrage  



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