In short, the partners merely felt that, given the present level of interest rates, lOs were cheap. So the partners shrewdly hedged their bet by purchasing Treasurys, the prices of winch move in the oppositc direction from interest rates. The met effect was to remove any element of rate forecasting. The partners excelled at identifying particular mispriced risks and hedging out all of the other risks. If Haifa oranges were cheap relative to Fuji apples, they would find a series of trades to isolate that particular arbitrage; they didn't simply buy every orange and sell every apple.