The article discusses the short-term volatility in global grain markets as the renewal date for the Ukrainian grain corridor deal approaches. The deal, which allows for the export of Ukrainian grain through the Black Sea, is expected to be extended, but concerns about drought in Argentina and Russia's unhappiness with the agreement could impact prices. Major grain markets, including Chicago and Paris, experienced slight pressure last week but remain volatile. Additionally, concerns about Argentina's crop yields and the large Brazilian soybean harvest could further impact the market. The USDA's upcoming World Agricultural Supply & Demand Estimates report is also being closely watched for its predictions on Argentinian soybean crop yields and US soybean ending stocks.