Estimates are presented of potential variability in real world price and its source. The estimated variance of potential deviations from trend has roughly doubled since 1960/61. The bulk of this variability is attributable to the effects of fluctuations in domestic production in LDC and CPC importers. The potential variability attributable to LDC production is increasing, and is further accentuated by their precautionary purchasing behavior. The key factor in market stability is the short-run responsiveness of U.S. wheat exports to price. Recent policy changes affecting the world market may increase future potential price instability by adding to market rigidity.