[quote]Queenleo 发表于 2009-8-9 20:39
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我认为套利和投机是不同的,arbitrageur是建立在对市场的理性分析的基础上,通过arbitrage赚取profit,buy at lower, sell at higher。和speculator是有一定区别的,投机者是抱着赌博的心态,通过自己对高度风险性的承担期望得到high return。所以hull把衍生品市场上的dealer分为了hedger,arbitrageur和speculator,所以后两者还是有区别的。
但是在现实中,我认为后两者的最终目的还是一样的,both for earning profit。
Part of your explanation is right. But the arbitrage is sell/short the overvalued one and buy/long undervalued one. Buying lower and sell higher is one leg of transaction. The arbitrageur also needs to sell/short overvalued leg and buy lower to lock the profit upfront.
According to Arbitrage Theory (ABT), by the law of one price, two instruments have same payoff, they should have same price, otherwise there is arbitrage opportunity. Keep in mind that two important assumptions in ABT are 1) the market is efficient; 2) the investors are rational. Then, the profit can be realized when the market prices of two instruments can converge to same. So sometime the arbitrageur can incur huge losses due to irrational behaviors of market ( Note:that's why behavior finance theory is becoming more popular now). The hedge fund, Long Term Capital Management failure is the best example of risk in arbitrage.
is a strategy to remove the market risk. You lock in the payoff and is not affected by . The risk left is the credit risk, that is, you will loss if the counterparty of future does not honor the contract.