Wheat price sees its biggest swings since 2011

Wheat prices swung more than 3 percent on five occasions in the past nine days, the first time that has happened since 2011, according to data compiled by Bloomberg. A drought spreading over the US plains sent Chicago futures to the biggest one-day gain this year, while data showing ample grain stockpiles erased most of the advance the next day.

Weather conditions are coming to the forefront as crops in the main growing areas of the Northern Hemisphere emerge from winter dormancy and enter key growth stages that determine production. At the same time, speculation over whether a Russian tax on wheat exports will be extended and the effects of the weakening euro are adding to volatility.

"Market participants don't really know if they've got to buy or if they've got to sell," Benjamin Bodart, a director at market consultant CRM Agri-Commodities in Newmarket, England, said. "The next major factor to keep an eye on is the weather."