Despite rising global production and stocks over the past few years, uncertainty about exportable supplies has caused major price swings in the last 18 months. The spike in early 2008 was quick and smooth, but the ride down has been slow and filled with bumps, as traders try to navigate the changing landscape of government restrictions. Export bans have been stringent at times and porous at others. Domestic purchase programs have pulled supplies from the international market only to release them later, sometimes in huge quantities. Unable to predict the availability of supplies, traders often react to rumors and fear, rather than supply and demand factors. This uncertainty destabilizes the market and causes price volatility.

Thai 100B quotes have been especially bumpy, sometimes above U.S. #2/4 quotes and other times below. Since January, the spread has changed directions at least three times with a maximum spread of $67 (U.S. over Thai) and a minimum of negative $97. From 1990 through 2007, the average spread was $81 and never went below negative $8.