AbstractThis paper examines the short‐term market reaction of four agricultural commodities to the Russian–Ukraine war and various stages of the Black Sea Grain Initiative Agreement. Using an event study, the results show a positive abnormal return for the agricultural grain markets with the outbreak of the war and the nonrenewal of the Black Sea Grain Agreement. These two events by causing supply‐side constraints, led to an increase in the price of grains. The results also show negative and statistically significant abnormal returns around the signing of the Black Sea Grain Agreement, its implementation through the departure of the first ship loaded with Ukrainian grain after the beginning of the war and the successive extensions of the agreement. These disruptions not only affect Ukraine and Russia but also have critical implications for world food security. Policy implications of our findings are provided.