All of Arthur_B.'s Comments + Replies

There is a googleable paper "the limits of arbitrage" by Shleifer which explains this concept in detail. Well worth the read There are other ways to get an excess return. They are all hard to do. Here is a partial list. * Exploit (or serve) someone else's need for liquidity. People buying in Japan now may be doing this. * Taxation arbitrage. Provide trades that allow someone else to improve their after-tax position eg splitting a bond into coupon payments (tax-free to a non-profit) and capital gains (taxable at a concessional rate to other people). * Exploit agency problems. Eg If you can take the other side of a trade from someone who is trying to massage short term earnings regardless of longer term impact you can win. One example of this is trend following, where you mostly lose, but occasionally win big. The other side of the trade is the counter-trend trader, who wins month after month (and gets big bonuses for doing so), then their employer has a big loss. But hey, the trader already got his bonuses. * Exploit large numbers of stupid people such as dot.com investors. Sometimes there are so many of them they overwhelm the smart money. By getting your timing right you can exploit them. George Soros does this a lot. * Exploit impatience. See Shleifer's article referenced above. For a fund manager, to win in the long term is useless, because his investors pulled their money long ago and his fund was closed down.